Expression of insulin-like growth factor binding protein 5 in the vaginal wall tissues of older women with pelvic organ prolapse

Abstract

Abstract Background Insulin-like growth factor binding protein 5 (IGFBP5) seems to be associated with aging and extracellular matrix (ECM) fibrosis, but there has been no examination of the expression and effect on vaginal wall tissues among pelvic organ prolapse (POP) patients. Objective This study aimed to investigate the expression and significance of IGFBP5 and ECM related proteins in anterior vaginal wall tissues among aged POP patients. Methods Tissues from the anterior vaginal wall were collected from 28 patients with POP and 20 patients without POP. The expression of protein and mRNA levels of IGFBP5 and ECM related proteins were evaluated in the vaginal wall tissues using immunohistochemistry, western blotting, and RT-qPCR techniques. The expression levels were then compared with clinical parameters. Results The expression levels of protein and mRNA of IGFBP5, collagen I, and collagen III were significantly lower in the POP group. Protein and mRNA expression levels of MMP2 were significantly higher in the POP group. IGFBP5 protein and mRNA expression levels were were negatively correlated with age and significantly lower in older POP patients (≥ 65 years old) compared to younger POP patients (< 65 years old). IGFBP5 protein and mRNA expression levels were also significantly lower in POP-Q stage IV patients compared to POP-Q stage III patients. Conclusion Downregulation of IGFBP5 may be related to alteration of the ECM and the IGFBP5 expression level is negatively correlated with the age and severity of prolapse. The significant decrease in IGFBP5 expression may play a crucial part in the aging process and the occurrence of POP.