Objectives: Pelvic organ prolapse is associated with defects in connective tissue including elastic fibers. The purpose of this study was to investigate expression of fibulin-5 and lysyl oxidase-like 1, which play an essential role in synthesis and assembly of elastic fibers in the uterosacral ligament, in samples taken from women with advanced pelvic organ prolapse compared with controls.
Study design: Specimens were obtained prospectively during abdominal hysterectomy from 30 women with advanced pelvic organ prolapse and 30 controls matched to the study group for age and parity among postmenopausal women with benign gynecologic pathology. Expression levels of protein and mRNA of fibulin-5 and lysyl oxidase-like 1 in uterosacral ligaments were measured by Western blot analysis and real-time quantitative polymerase chain reactions. For statistical analyses, Student's t-test, chi-square test, Mann-Whitney U test, Fisher's exact test and Spearman's correlation were used.
Results: Significant decrease in the expression of mRNA of fibulin-5 was found in patients with prolapse (P-value=0.042; 0.743+/-0.229 and 1.061+/-0.537). The expression of mRNA of lysyl oxidase-like 1 was increased in the patient group (P-value=0.017; 4.099+/-2.832 and 1.816+/-1.602). Similar results were shown in Western blot analysis. Differences in expression of fibulin-5 and lysyl oxidase-like 1 were noted according to stage of prolapse (P-value=0.037 and 0.009).
Conclusions: There was decreased expression of fibulin-5 and increased expression of lysyl oxidase-like 1 in uterosacral ligaments in patients with pelvic organ prolapse, which suggests the possibility of defects in elastin synthesis.