Changes in mitochondrial DNA copy number and extracellular matrix (ECM) proteins in the uterosacral ligaments of premenopausal women with pelvic organ prolapse

Objective The study aimed to explore the changes in mitochondrial DNA (mtDNA) copy number, collagen, and matrix metalloproteinase (MMPs) expression with pelvic organ prolapse (POP) in the uterosacral ligaments of premenopausal women. Materials and methods A group of 56 premenopausal women, all younger than 52 years of age, were enrolled in this study. Uterosacral ligament (UL) biopsies were obtained from uterine specimens taken from 22 women with POP ( n = 22, study group) and 34 myoma patients without POP ( n = 34, control group) during abdominal or vaginal hysterectomy. Quantitative real-time polymerase chain reaction (Q-PCR) and immunohistochemistry analysis were applied in the present study. Results The rate of high body mass index (BMI) (> 24 kg/m 2 ) women was significantly higher in the POP group (81.8% vs. 35.3%, p = 0.001 *), and the BMI of the POP women was higher than that of the nonPOP women ( p = 0.029 *). The mtDNA copy number ( p = 0.001 *), collagen III alpha 1 (COL3α1) expression ( p = 0.025 *), and MMP2 expression ( p = 0.047 *) were significantly higher in the POP group when compared with the nonPOP group. The high BMI women had a higher mtDNA copy number ( p = 0.002 *), COL3α1 ( p = 0.028 *) gene expressions compared with the standard BMI women. Conclusion In the premenopausal state, higher BMI may be a stronger associate factor than vaginal birth for the development of POP. The higher mtDNA copy number, COL3α1, and MMP2 gene expressions are highly associated with POP in the UL of premenopausal women.