title: Epidermal aquaporin-3 is increased in the cutaneous burn wound.
abstract: BACKGROUND
  Aquaporins (AQP) are a family of transmembrane proteins that transport water and small solutes such as glycerol across cell membranes. It is a mediator of transcellular water flow and plays an important role in maintaining intra/extracellular fluid homeostasis by facilitating water transport in response to changing osmotic gradients. In the skin, AQPs permit rapid, regulated, and selective water permeability and have been demonstrated to play a role in skin hydration, cell proliferation, migration, immunity, and wound healing. However, the expression of AQP-3 in the cutaneous burn wound has never been elucidated. We sought to assess the expression of AQP-3 in patients with burn wounds.
  
  
  METHODS
  A fresh full thickness biopsy sample was taken from the center of the burn wound, the burn wound edge, and the graft donor site in 7 patients (n=21), approximately 3-7 days post injury. Fixed, paraffin embedded sections were stained using AQP-3 specific antibody and examined by immunofluorescence. Fresh samples were processed to quantify AQP-3 protein expression with Western blot analysis.
  
  
  RESULTS
  The central portion of the burn wound revealed destruction of the epidermis and dermis with no AQP-3 present. Along the burn wound edge where the epidermal architecture was disrupted, there was robust AQP-3 staining. Western blot analysis demonstrated deeper staining along the burn wound edge compared to unburned skin (control). Quantification of the protein shows a significant amount of AQP-3 expression along the burn wound edge (3.6±0.34) compared to unburned skin (2.1±0.28, N=7, *p<0.05). There is no AQP-3 expression in the burn wound center.
  
  
  CONCLUSIONS
  AQP-3 expression is increased in the burn wound following injury. While its role in wound healing has been defined, we report for the first time the effect of cutaneous burns on AQP-3 expression. Our data provides the first step in determining its functional role in burn wounds. We hypothesize that development of AQP3 targeted therapies may improve burn wound healing.
authors.affiliation: University School of Medicine, Department of Plastic and Reconstructive/Burn Surgery, 4940 Eastern Avenue, Baltimore, MD 21224, United States.
authors.forename: R
authors.initials: R
authors.lastname: Sebastian
authors.affiliation: University School of Medicine, Department of Pulmonary and Critical Care Medicine, 1830 E. Monument St., 5th Floor, Baltimore, MD 21205, United States.
authors.forename: E
authors.initials: E
authors.lastname: Chau
authors.affiliation: University School of Medicine, Department of Plastic and Reconstructive/Burn Surgery, 4940 Eastern Avenue, Baltimore, MD 21224, United States.
authors.forename: P
authors.initials: P
authors.lastname: Fillmore
authors.affiliation: University School of Medicine, Department of Plastic and Reconstructive/Burn Surgery, 4940 Eastern Avenue, Baltimore, MD 21224, United States.
authors.forename: J
authors.initials: J
authors.lastname: Matthews
authors.affiliation: University School of Medicine, Department of Plastic and Reconstructive/Burn Surgery, 4940 Eastern Avenue, Baltimore, MD 21224, United States.
authors.forename: L A
authors.initials: LA
authors.lastname: Price
authors.affiliation: University School of Medicine, Department of Pulmonary and Critical Care Medicine, 1830 E. Monument St., 5th Floor, Baltimore, MD 21205, United States.
authors.forename: V
authors.initials: V
authors.lastname: Sidhaye
authors.affiliation: University School of Medicine, Department of Plastic and Reconstructive/Burn Surgery, 4940 Eastern Avenue, Baltimore, MD 21224, United States. Electronic address: smilner3@jhmi.edu.
authors.forename: S M
authors.initials: SM
authors.lastname: Milner
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D051400:Aquaporin 3 / Q000378:metabolism*; D015153:Blotting, Western; D002056:Burns / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D016022:Case-Control Studies; D015331:Cohort Studies; D020405:Dermis / Q000378:metabolism* / Q000473:pathology; D004817:Epidermis / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010539:Permeability; D012867:Skin / Q000378:metabolism / Q000473:pathology; D016038:Skin Transplantation; D055815:Young Adult
chemical_list: C496027:AQP3 protein, human; D051400:Aquaporin 3
keywords: Aquaporin; Burns; Epidermis