Proliferative behavior of vaginal fibroblasts from women with pelvic organ prolapse Bin Sun a,e,1 , Lu Zhou a,d,1 , Yan Wen a, *, Chenhong Wang d , Thomas M. Baer c , Renee R. Pera a,b , Bertha Chen a a Department of Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, CA, USA b Institute for Stem Cell Biology & Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, USA c Department of Applied Physics, Stanford University, Stanford, CA, USA d Maternity and Children’s Healthcare Hospital of Shenzhen City, Shenzhen, China e Guangzhou Medical University, Guangzhou, China Introduction Pelvic organ prolapse (POP) is a common condition with significant impact on the quality of life of menopausal women. Despite the high prevalence and recurrence rates after surgical repair, its cellular pathophysiology is still not well understood. Structural defects in the vagina and its supportive tissues are speculated to be one of the mechanisms that predisposes a woman to POP [1]. The extracellular matrix in these supportive tissues consists of proteins such as collagen and elastin fibers that contribute to the biomechanical properties of the vagina. This matrix is laid down primarily by fibroblasts [2]. Hung et al. observed that vaginal fibroblasts exhibiting high collagen I/III ratios in cell culture also had higher proliferative rates [3]. Conse- quently, changes in fibroblast proliferation and behavior may alter extracellular matrix turnover in the vagina, ultimately contribut- ing to the pathogenesis of POP. Because the prevalence of POP increases with age, several studies have examined the effect of aging on fibroblasts [3–5]. European Journal of Obstetrics & Gynecology and Reproductive Biology 183 (2014) 1–4 A R T I C L E I N F O Article history: Received 23 April 2014 Received in revised form 8 September 2014 Accepted 29 September 2014 Keywords: Vaginal fibroblasts Cell proliferation Mitotic index Time-lapse dark-field microscopy TGF-b1 A B S T R A C T Objective: Pelvic organ prolapse (POP) significantly impacts quality of life of women, especially with advancing age. Cell proliferation is a critical parameter in both normal and pathophysiological processes. We sought to examine fibroblast proliferation in premenopausal women with and without POP and menopausal women with POP, and examine whether TGF-b1, a fibroblast mitogen, could stimulate proliferation in vaginal fibroblasts from these populations. Study design: Vaginal wall biopsies were obtained from asymptomatic women (controls) and women with POP (cases). Fibroblasts were cultured from these tissues. Vaginal fibroblasts were treated with or without TGF-b1. Cell proliferation rate (mitotic index) was measured with time-lapse dark-field microscopy. Cell mitosis was counted with ImageJ software after analysis of time-lapse images as Quick time movies. Results: There was no significant difference in mitotic index throughout different time points of observation between premenopausal controls and cases of similar ages. However, a significant difference in mitotic index was seen between premenopausal and menopausal cases (p = 0.01), with the menopausal group exhibiting significantly lower mitotic indices. When treated with different doses of TGF-b1, premenopausal control fibroblast proliferation increased with 5 ng/ml of TGF-b1 compared to non-treated fibroblasts (p = 0.04). TGF-b1 stimulation did not affect fibroblasts from either premenopausal or menopausal cases. Conclusions: Vaginal fibroblast proliferation decreases with age and this association does not appear to be affected by the presence of pelvic organ prolapse. TGF-b1 stimulation increased cell proliferation of premenopausal control fibroblasts. In contrast, there was no response seen in fibroblasts from premenopausal and menopausal cases. ß 2014 Elsevier Ireland Ltd. All rights reserved. * Corresponding author at: G323, Department of Obstetrics/Gynecology, Stanford University School of Medicine, Stanford, CA 94305-5317, USA. Tel.: +1 650 723 9536; fax: +1 650 723 7737. E-mail address: yanwen@stanford.edu (Y. Wen). 1 These authors contributed equally to this study. Contents lists available at ScienceDirect European Journal of Obstetrics & Gynecology and Reproductive Biology jou r nal h o mep ag e: w ww .elsevier .co m /loc ate/ejo g rb http://dx.doi.org/10.1016/j.ejogrb.2014.09.040 0301-2115/ß 2014 Elsevier Ireland Ltd. All rights reserved.