title: Acute effects of fractional laser on photo-aged skin.
abstract: BACKGROUND
  Nonablative fractional photothermolysis (FP) laser treatment has shown clinical efficacy on photo-aged skin. Few studies have examined the molecular responses to FP.
  
  
  OBJECTIVE
  To characterize the dynamic alterations involved in dermal matrix remodeling after FP laser treatment.
  
  
  METHODS
  A single multipass FP treatment was performed. Baseline, day 1, and day 7 biopsies were obtained. Biopsies were sectioned and stained for histology and immunofluorescence confocal microscopic. Heat shock protein-70 (HSP-70) and matrix metalloproteinase-1 (MMP-1) expression and extracellular matrix (ECM) autofluorescence were examined. Quantitative real-time polymerase chain reaction (qRT-PCR) experiments were performed probing for collagen 1A1 (COL1A1) and COL3A1.
  
  
  RESULTS
  All three patients were Caucasian women aged 49, 62, and 64 with Fitzpatrick skin types II, III, and IV. Transient neutrophilic infiltration found on day 1. Protein expression of HSP-70 and MMP-1 were up-regulated on day 1, reverting to baseline by day 7. ECM autofluorescence decreased from baseline to day 7. qRT-PCR showed a minor decrease in COL1A1 and COL3A1 messenger RNA 1 day after treatment. Variable results between patients receiving equal treatment were evident.
authors.affiliation: Department of Dermatology, University Hospitals of Case Medical Center, Case Western Reserve University, Cleveland, Ohio, USA.
authors.forename: Autumn M
authors.initials: AM
authors.lastname: Starnes
authors.forename: Paul C
authors.initials: PC
authors.lastname: Jou
authors.forename: Jason K
authors.initials: JK
authors.lastname: Molitoris
authors.forename: Minh
authors.initials: M
authors.lastname: Lam
authors.forename: Elma D
authors.initials: ED
authors.lastname: Baron
authors.forename: Jorge
authors.initials: J
authors.lastname: Garcia-Zuazaga
mesh_terms: D001706:Biopsy; D020405:Dermis / Q000473:pathology* / Q000528:radiation effects; D005109:Extracellular Matrix / Q000473:pathology / Q000528:radiation effects; D005260:Female; D006801:Humans; D053685:Laser Therapy; D008875:Middle Aged; D015595:Skin Aging / Q000528:radiation effects*; D014945:Wound Healing