Immunohistochemical expression of hypoxia-inducible factor-1α in stromal cells of vaginal tissue in post-menopausal women with pelvic organ prolapse.

Background & objectives: Pelvic organ prolapse (POP) is a common medical condition that affects adult women of different ages. The support of a normal pelvic floor is the result of complex interactions between ligaments, muscles, connective tissue and vaginal walls. Hypoxia and oxidative stress can reduce protein synthesis in the pelvic muscles that may contribute to muscular atrophy. Hypoxia-inducible factor-1α (HIF-1α) is a transcriptional activator which, expressed in response to hypoxia, activates a number of genes involved in cellular response to hypoxia. However, a potential role of hypoxia and oxidative stress in pathogenesis of POP is not known. This study was aimed to compare the level of HIF-1α immunohistochemical expression in the vaginal stromal cells of postmenopausal women with and without POP. Methods: Samples of the vaginal tissue from 120 menopausal women were obtained during surgery, and immunohistochemical expression of HIF-1α was assessed. There were 60 women with POP while 60 women in the control group were without prolapse but with benign gynaecological diseases. Results: In post-menopausal women with prolapse, significant differences were observed in the number of HIF-1α-positive stromal cells in the vaginal tissue compared to the control group. There was a significant increase in the number of HIF-1α in the stromal cells of the vaginal tissue in women with prolapse. Interpretation & conclusions: Difference in expression of HIF-1α in stromal cells of the vaginal tissue in the post-menopausal women with and without POP suggests that prolonged hypoxia probably has an important role in the aetiopathogenesis of POP.