Identification of protein marker in vaginal wall tissues of women with stress urinary incontinence by protein chip array

• Published in: The journal of obstetrics and gynaecology research 2012-01, Vol.38 (1), p.89-96
• Main Authors: Wen, Yan, Whitin, John, Yu, Tom, Cohen, Harvey, Polan, Mary Lake, Chen, Bertha
• Format: Article
• Language: English
• Subjects: Adult; Biomarkers; Biomarkers - metabolism; Desorption; Female; Humans; Immunohistochemistry; Mass spectrometry; Mass spectroscopy; Microfilament Proteins - metabolism; Muscle Proteins - metabolism; myofibroblast; Protein arrays; protein chip array; Proteins; Scientific imaging; SM-22α; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; stress urinary incontinence; Trypsin; Urinary incontinence; Urinary Incontinence, Stress - metabolism; Vagina; Vagina - metabolism
• ISSN: 1341-8076; 1447-0756; 1341-8076
• DOI: 10.1111/j.1447-0756.2011.01690.x

Aim:  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. Material and Methods:  We compared protein expression profile of vaginal tissue from women with SUI and continent controls. A 22.6 kDa 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 22.6 kDa 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. Conclusion:  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.