J Obstet Gynaecol Res. 2012 Jan;38(1):89-96. doi: 10.1111/j.1447-0756.2011.01690.x. Epub 2011 Dec 5.

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

Wen Y¹, Whitin J, Yu T, Cohen H, Polan ML, Chen B.

Author information

1: Department of Obstetrics and Gynecology Pediatrics, Stanford University School of Medicine, Stanford, CA 94305, USA. yanwen@stanford.edu

Abstract

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 22.6kDa 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.

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.