title: Clinical improvement following dermabrasion of photoaged skin correlates with synthesis of collagen I.
abstract: METHODS
  The ability of superficial dermabrasion to improve clinical features of photoaged skin is well known, but the specific biological mechanisms involved are poorly understood. The so-called repair zone, as visualized by routine histologic examination, has been attributed to new collagen formation within the papillary dermis and may be responsible for clinical improvement following dermabrasion. We investigated molecular and histologic events occurring in dermabraded skin and correlated them with clinical improvement. Ten photoaged patients (mean age, 59 years) underwent facial dermabrasion to the level of the papillary dermis. Clinical severity of photoaging was graded in a blinded manner at baseline and 12 weeks after dermabrasion. Biopsy specimens obtained at baseline and 3 and 12 weeks after dermabrasion were analyzed histologically and by in situ hybridization for fibroblast procollagen I mRNA, immunohistologically and by Western blotting with a monoclonal antibody specific for the aminoterminal cleavage site of procollagen I.
  
  
  RESULTS
  Masson's trichrome staining demonstrated an increase in collagen from baseline (as an upper dermal band in the dermabrasion "repair zone") at 3 and 12 weeks' postdermabrasion. Immunohistologic examination demonstrated papillary dermal fibroblast staining for procollagen I at baseline that increased by threefold at 3 weeks' postdermabrasion and by 1.5-fold at 12 weeks' postdermabrasion. Western blotting demonstrated an average-fold increase in pN collagen I of 4.2 +/- 1.5 at 3 weeks and of 2.7 +/- 0.7 at 12 weeks. By in situ hybridization, baseline levels of procollagen I mRNA in papillary dermal fibroblasts increased sixfold at weeks 3 and 12 postdermabrasion. Increase in procollagen I mRNA correlated with clinical improvement, ie, reduction in wrinkling.
  
  
  CONCLUSIONS
  Superficial dermabrasion clinically improves photoaged skin, and this improvement correlates strongly with increased collagen I gene expression.
authors.affiliation: Department of Dermatology, University of Michigan, Ann Arbor.
authors.forename: B R
authors.initials: BR
authors.lastname: Nelson
authors.forename: G
authors.initials: G
authors.lastname: Majmudar
authors.forename: C E
authors.initials: CE
authors.lastname: Griffiths
authors.forename: M O
authors.initials: MO
authors.lastname: Gillard
authors.forename: A E
authors.initials: AE
authors.lastname: Dixon
authors.forename: A
authors.initials: A
authors.lastname: Tavakkol
authors.forename: T A
authors.initials: TA
authors.lastname: Hamilton
authors.forename: R A
authors.initials: RA
authors.lastname: Woodbury
authors.forename: J J
authors.initials: JJ
authors.lastname: Voorhees
authors.forename: T M
authors.initials: TM
authors.lastname: Johnson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003094:Collagen / Q000032:analysis / Q000096:biosynthesis*; D003869:Dermabrasion; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011347:Procollagen / Q000032:analysis; D012867:Skin / Q000737:chemistry; D015595:Skin Aging / Q000473:pathology / Q000502:physiology*
chemical_list: D011347:Procollagen; D003094:Collagen