Comparative Study On Proteomes Between Pelvic Organ Prolapse And Control Women's Vaginal Tissues

【Objective】To establish the two-dimensional gel electrophoresis (2-DE) patterns of the vaginal tissue protein, analyze the differentially expressed proteins in vaginal tissues from women with pelvic organ prolapse (POP) compared with asymptomatic women by 2-DE and mass spectrometry, and find out the POP-related proteins. To investigate the pathogenesis of POP by analyzing the POP-related proteins.【Methods】1. The periurethral vaginal wall tissues of ten pairs of postmenopausal, age-matched POP and control women were collected during operation. The samples were preserved in the -80℃supercold refrigerator.2. Total protein was extracted and separated on two-dimensional gel electrophoresis. The two-dimensional gel electrophoresis patterns underwent matched-analysis and differential-analysis using ImageMaster5.0 2D image analysis software to find the differentially expressed protein spots between two groups.3. Some of the differentially expressed protein spots were in-gel digested and identified by MALDI-TOF-MS to obtain peptide mass fingerprint (PMF). Protein was identified by PMF and database searching.【RESULTS】The two-dimensional gel electrophoresis patterns of the vaginal wall tissues from POP and control group had high resolution and good repeatability. The image analysis showed that the average protein spots were 871±96 and 856±89 in POP and the normal control group respectively. The protein spots on gel had a well repeatability for position. The average position deviation of matched spots was 1.73±0.18 mm in isoelectrofocusing direction and 1.87±0.22 mm in SDS-PAGE direction. A total of 109±15 spots were not matched. There were 27 distinct protein spots whose expressing levels had a difference greater than 2 folds. Eight of which were performed for mass spectrometry and 5 proteins were obtained. They were keratin 13, keratin 1, transgelin, cysteine and glycine-rich protein 1 (CRP1) and T-bet respectively. Transgelin and CRP1 only expressed in POP group, T-bet only expressed in control group, and the control group expressed keratin 13 and keratin 1 six folds more than the POP group did.【CONCLUSIONS】1. It is feasible to research POP disease-related proteins by two-dimensional gel electrophoresis and mass spectrometry.2. The down-regulation of keratin 13 and keratin 1 in POP vaginal tissue suggest that the differentiation of vaginal epithelium is suppressed. It results in vaginal epithelium becoming thin and affects the supporting role of vaginal wall. As a result, patients are prone to POP.3. Transgelin is only expressed in POP vaginal tissue. It is known that transgelin suppress the function of MMP-9. Moreover, previous study has demonstrated an increase in collagen III expression in POP vaginal tissue. Therefore, we speculate that it results in the accumulation of type III collagen in POP vaginal tissue and the imbalance of the ratio of collagen I to collagen III. As a result, the tensile strength of vaginal tissue weakens and prolapse occurs.4. CRP1 is the essential positive regulator of muscle differentiation. It is only expressed in POP vaginal tissue and might be related to the compensatory repair of vaginal smooth muscle after damage.5. T-bet is only expressed in control vaginal tissue and can't be detected in POP. We speculate that which results in weak immune defense of the POP vaginal tissue. Therefore, the POP vaginal tissue is attacked and destroyed easily by pathogen.