Is There a Relationship Between Pelvic Organ Prolapse and Tissue Fibrillin-1 Levels?

Abstract

Purpose: Pelvic organ prolapse is a multifactorial disorder in which extracellular matrix defects are implicated. Fibrillin-1 level is reduced in stress urinary incontinence. In Marfan syndrome, which is associated with mutations in Fibrillin-1, pelvic floor disorders are commonly observed. We hypothesize that Fibrillin-1 gene expression is altered in pelvic organ prolapse.

Methods: Thirty women undergoing colporrhaphy or hysterectomy because of cystocele, rectocele, cystorectocele, or uterine prolapse were assigned to a pelvic prolapse study group, and thirty women undergone hysterectomy for nonpelvic prolapse conditions were assigned to a control group. Real-time polymerase chain reaction was conducted on vaginal tissue samples to measure the expression of Fibrillin-1. Expression levels were compared between study and control groups by Mann-Whitney U test with Bonferroni revision.

Results: Fibrillin-1 gene expression was not significantly lower in the study group than in the control group. Similarly, no significant correlation between Fibrillin-1 levels and grade of pelvic prolapse was found. Age over 40 years (P=0.018) and menopause (P=0.027) were both associated with reduced Fibrillin-1 levels in the pelvic prolapse group, whereas the delivery of babies weighing over 3,500 g at birth was associated with increased Fibrillin-1 expression (P=0.006).

Conclusions: The results did not indicate a significant reduction in Fibrillin-1 gene expression in pelvic prolapse disorders; however, reduced Fibrillin-1 may contribute to increased pelvic organ prolapse risk with age and menopause. Increased Fibrillin-1 gene expression may be a compensatory mechanism in cases of delivery of babies with high birth weight. Further studies are needed for a better understanding of these observations.

Keywords: Extracellular Matrix; Fibrillin; Pelvic Organ Prolapse.

Fig. 1.

Amplification plots of Fibrillin-1 mRNA (A) and housekeeping β-actin mRNA (B). Serial dilutions of Fibrillin-1 and β-actin cDNA plasmids were prepared and amplification was performed by quantitative real-time polymerase chain reaction. For each dilution, fluorescence is plotted against the cycle number. Log concentration and cycle numbers of each dilution are shown. Serial dilutions of Fibrillin-1 and β-actin cDNA plasmids were prepared and amplification was performed. Log concentrations of Fibrillin-1 mRNA (C) and β-actin mRNA (D) were plotted against the cycle number.