Vaginal smooth muscle cell apoptosis is increased in women with pelvic organ prolapse

Abstract

To compare the smooth muscle content and apoptosis of the vagina in women with and without anterior vaginal wall prolapse. Vaginal tissues were sampled in women with (n = 6) or without (n = 6) anterior vaginal wall prolapse undergoing hysterectomy. Smooth muscle of the vagina was studied by immunohistochemistry. Digital image analysis was used to determine the fractional area of smooth muscle in the histologic cross-sections. Apoptosis was assessed by TUNEL assay. The fractional area of non-vascular smooth muscle in the vagina of women with anterior vaginal wall prolapse was significantly decreased compared to women without prolapse (0.36 +/- 0.12 vs. 0.16 +/- 0.12 P = 0.021) and the apoptotic index was significantly higher compared to women without prolapse (0.04 +/- 0.01 vs. 0.02 +/- 0.03, P = 0.041). The fraction of smooth muscle in the vagina is significantly decreased and the rate of apoptosis is higher in women with anterior vaginal wall prolapse compared to women without prolapse.

Histology of the vaginal wall in women with pelvic organ prolapse: a literature review

“…Many other reports have published concordant results with the study by Boreham et al (Table 3) [27][28][29][30]. The fraction of smooth muscle in the muscularis of the anterior vaginal wall was significantly decreased in women with POP and there was no significant difference between primary and recurrent cases.…”

“…Several studies suggest that changes in the morphometry of the vagina, particularly at the muscularis layer, may affect the function of the tissue and contribute to the development of POP [6,28]. Although these changes are often observed, the mechanism of this transformation is still unclear.…”

“…The fraction of smooth muscle in the muscularis of the anterior vaginal wall was significantly decreased in women with POP and there was no significant difference between primary and recurrent cases. Takacs et al also observed a statistically significantly increased smooth muscle cell apoptotic index in women with POP, suggesting that a decrease in the amount of smooth muscle in the anterior vaginal wall might be due to accelerated apoptosis [28].…”

Tissu conjonctif de soutien et genèse des prolapsus

“…En particulier, une alté ration de la biosynthè se du collagè ne ou de l'é lastine, conduisant à une perte d'é lasticité des fibres musculaires du tissu conjonctif, a é té rapporté e par plusieurs é tudes [15][16][17][18][19][20][21]. La fré quence de l'incontinence et des prolapsus gé nitaux associé e aux maladies gé né -tiques du collagè ne (syndrôme de Marfan ou d'Ehlers-Danlos) confirme le rôle de cette proté ine et plus globalement, de l'importance d'un tissu de soutien normal dans la physiopathologie des prolapsus [23,24].…”

“…infra, causes gé né tiques) et contribuer aux troubles de la statique pelvienne. Par ailleurs, une diminution du nombre des cellules musculaires lisses [18,22], tout comme des anomalies de leur structure au niveau du 1/3 cervical des ligaments uté rosacré s [20] ou de la paroi anté rieure du vagin [19] ont é té rapporté es chez des femmes porteuses d'un prolapsus, avec dé sorganisation des bandes musculaires et diminution de l'immunomarquage pour l'actine. La mise en é vidence de telles anomalies chez les femmes non mé nopausé es [19] serait plus de nature à té moigner du rôle de facteurs gé niques de pré disposition que d'un effet environnemental ou lié à l'âge et même si l'impact de ces derniers ne peut être complè tement exclu.…”