title: Topically applied growth factors change skin cytoplasmic creatine kinase activity and distribution and produce abnormal keratinocyte differentiation in murine skin.
abstract: OBJECTIVE
  The skin has a functional and active phosphocreatine (PCR)/creatine kinase (CPK) system that regenerates adenosine triphosphate energy reserves during periods of ischemia. The objective of this study was to evaluate how topically applied growth factors affect CPK activity and distribution, and what histological changes growth factors induce in murine skin.
  
  
  METHODS
  Epidermal growth factor (EGF), transforming growth factor alpha (TGF-alpha) and suramin (growth factor inhibitor) were applied to murine skin for nine days before mice were sacrificed and CPK level and distributions were measured.
  
  
  RESULTS
  TGF-alpha considerably increased CPK activity. Both EGF and TGF-alpha induced a CPK MM to CPK BB transition and histologically induced abnormal differentiation of keratinocytes.
  
  
  CONCLUSIONS
  The skin PCR/CPK system is affected by growth factors. Furthermore, this system appears to play an important role, both in the normal physiology of skin and pathophysiological conditions such as psoriasis and carcinogenesis.
authors.affiliation: Department of Dermatology, Indiana University School of Medicine, Muncie, IN 47303, USA. azemtsov@IUPUI.edu
authors.forename: Alexander
authors.initials: A
authors.lastname: Zemtsov
authors.forename: Victor
authors.initials: V
authors.lastname: Montalvo-Lugo
mesh_terms: D000287:Administration, Topical; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D003402:Creatine Kinase / Q000378:metabolism*; D003593:Cytoplasm / Q000201:enzymology; D004789:Enzyme Activation / Q000187:drug effects; D004815:Epidermal Growth Factor / Q000008:administration & dosage*; D036341:Intercellular Signaling Peptides and Proteins / Q000008:administration & dosage; D015603:Keratinocytes / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology*; D008297:Male; D051379:Mice; D012867:Skin / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology*; D014018:Tissue Distribution / Q000187:drug effects; D016211:Transforming Growth Factor alpha / Q000008:administration & dosage*
chemical_list: D036341:Intercellular Signaling Peptides and Proteins; D016211:Transforming Growth Factor alpha; D004815:Epidermal Growth Factor; D003402:Creatine Kinase