title: Identification of protein marker in vaginal wall tissues of women with stress urinary incontinence by protein chip array.
abstract: OBJECTIVE
  We sought to investigate protein biomarkers for stress urinary incontinence (SUI) in vaginal tissues using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) and examine if this is a reliable methodology to examine proteins in small tissue specimens.
  
  
  METHODS
  We compared protein expression profile of vaginal tissue from women with SUI and continent controls. A 22.6kDa peak was identified by subsequent weak cation-exchange, reverse-phase fractionation, gel electrophoresis, and trypsin digestion, then analyzed by matrix assisted laser desorption/ionization mass spectrometry (MALDI MS) and MALDI MS-MS. Biomarker identity and expression level were confirmed by Western-blotting and immunohistochemistry.
  
  
  RESULTS
  Expression of the 22.6kDa protein, identified as SM-22α, was significantly higher in women with SUI versus controls. A 3×3-mm tissue sample was sufficient for identification. Western-blot/immunohistochemistry confirmed the SELDI-TOS MS findings.
  
  
  CONCLUSIONS
  SM-22α, a marker for myofibroblasts, was identified as a biomarker of SUI. Differential protein profiling by SELDI-TOF MS is a powerful and reliable tool for urogynecological research as it allows us to study an array of proteins simultaneously using small tissue samples.
authors.affiliation: Department of Obstetrics and Gynecology Pediatrics, Stanford University School of Medicine, Stanford, CA 94305, USA. yanwen@stanford.edu
authors.forename: Yan
authors.initials: Y
authors.lastname: Wen
authors.forename: John
authors.initials: J
authors.lastname: Whitin
authors.forename: Tom
authors.initials: T
authors.lastname: Yu
authors.forename: Harvey
authors.initials: H
authors.lastname: Cohen
authors.forename: Mary Lake
authors.initials: ML
authors.lastname: Polan
authors.forename: Bertha
authors.initials: B
authors.lastname: Chen
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D005260:Female; D006801:Humans; D008840:Microfilament Proteins / Q000378:metabolism; D009124:Muscle Proteins / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014550:Urinary Incontinence, Stress / Q000378:metabolism*; D014621:Vagina / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D008840:Microfilament Proteins; D009124:Muscle Proteins; C051615:transgelin