Vaginal Smooth Muscle Cells Research Articles

Biophysical Mechanisms of Vaginal Smooth Muscle Contraction: The Role of the Membrane Potential and Ion Channels.

The vagina is an essential component of the female reproductive system and is responsible for providing female sexual satisfaction. Vaginal smooth muscle contraction plays a crucial role in various physiological processes, including sexual arousal, childbirth, and urinary continence. In pathophysiological conditions, such as pelvic floor disorders, aberrations in vaginal smooth muscle function can lead to urinary incontinence and pelvic organ prolapse. A set of cellular and sub-cellular physiological mechanisms regulates the contractile properties of the vaginal smooth muscle cells. Calcium influx is a crucial determinant of smooth muscle contraction, facilitated through voltage-dependent calcium channels and calcium release from intracellular stores. Comprehensive reviews on smooth muscle biophysics are relatively scarce within the scientific literature, likely due to the complexity and specialized nature of the topic. The objective of this review is to provide a comprehensive description of alterations in the cellular physiology of vaginal smooth muscle contraction. The benefit associated with this particular approach is that conducting a comprehensive examination of the cellular mechanisms underlying contractile activation will enable the creation of more targeted therapeutic agents to control vaginal contraction disorders.

Smooth muscle contribution to vaginal viscoelastic response

Smooth muscle cells contribute to the mechanical function of various soft tissues, however, their contribution to the viscoelastic response when subjected to multiaxial loading remains unknown. The vagina is a fibromuscular viscoelastic organ that is exposed to prolonged and increased pressures with daily activities and physiologic processes such as vaginal birth. The vagina changes in geometry over time under prolonged pressure, known as creep. Vaginal smooth muscle cells may contribute to creep. This may be critical for the function of vaginal and other soft tissues that experience fluctuations in their biomechanical environment. Therefore, the objective of this study was to develop methods to evaluate the contribution of smooth muscle to vaginal creep under multiaxial loading using extension – inflation tests. The vaginas from wildtype mice (C57BL/6 × 129SvEv; 3–6 months; n = 10) were stimulated with various concentrations of potassium chloride then subjected to the measured in vivo pressure (7 mmHg) for 100 s. In a different cohort of mice (n = 5), the vagina was stimulated with a single concentration of potassium chloride then subjected to 5 and 15 mmHg. A laser micrometer measured vaginal outer diameter in real-time. Immunofluorescence evaluated the expression of alpha-smooth muscle actin and myosin heavy chain in the vaginal muscularis (n = 6). When smooth muscle contraction was activated, vaginal creep behavior increased compared to the relaxed state. However, increased pressure decreased the active creep response. This study demonstrated that extension – inflation protocols can be used to evaluate smooth muscle contribution to the viscoelastic response of tubular soft tissues.

The regulatory effect of sex steroids on the RhoA/ROCK pathway in the rat distal vagina.

Sex steroids have been demonstrated as important modulators of vaginal function. The RhoA/ROCK calcium-sensitizing pathway plays a role in genital smooth muscle contractile mechanism, but its regulation has never been elucidated. This study investigated the sex steroid regulation of the vaginal smooth muscle RhoA/ROCK pathway using a validated animal model. Ovariectomized (OVX) Sprague-Dawley rats were treated with 17β-estradiol (E2), testosterone (T), and T with letrozole (T + L) and compared with intact animals. Contractility studies were performed to test the effect of the ROCK inhibitor Y-27632 and the nitric oxide (NO) synthase inhibitor L-NAME. In vaginal tissues, ROCK1 immunolocalization was investigated; mRNA expression was analyzed by semiquantitative reverse transcriptase-polymerase chain reaction; and RhoA membrane translocation was evaluated by Western blot. Finally, rat vaginal smooth muscle cells (rvSMCs) were isolated from the distal vagina of intact and OVX animals, and quantification of the RhoA inhibitory protein RhoGDI was performed after stimulation with NO donor sodium nitroprusside, with or without administration of the soluble guanylate cyclase inhibitor ODQ or PRKG1 inhibitor KT5823. Androgens are critical in inhibiting the RhoA/ROCK pathway of the smooth muscle compartment in the distal vagina. ROCK1 was immunolocalized in the smooth muscle bundles and blood vessel wall of the vagina, with weak positivity detected in the epithelium. Y-27632 induced a dose-dependent relaxation of noradrenaline precontracted vaginal strips, decreased by OVX and restored by E2, while T and T + L decreased it below the OVX level. In Western blot analysis, when compared with control, OVX significantly induced RhoA activation, as revealed by its membrane translocation, with T reverting it at a level significantly lower than in controls. This effect was not exerted by E2. Abolishing NO formation via L-NAME increased Y-27632 responsiveness in the OVX + T group; L-NAME had partial effects in controls while not modulating Y-27632 responsiveness in the OVX and OVX + E2 groups. Finally, stimulation of rvSMCs from control animals with sodium nitroprusside significantly increased RhoGDI protein expression, counteracted by ODQ and partially by KT5823 incubation; no effect was observed in rvSMCs from OVX rats. Androgens, by inhibiting the RhoA/ROCK pathway, could positively contribute to vaginal smooth muscle relaxation, favoring sexual intercourse. This study describes the role of androgens in maintaining vaginal well-being. The absence of a sham-operated animal group and the use of the only intact animal as control represented a limitation to the study.

Overexpressing miR-122-5p Inhibits the Relaxation of Vaginal Smooth Muscle in Female Sexual Arousal Disorder by Targeting Vasoactive Intestinal Peptide Receptor 1.

IntroductionFemale sexual arousal disorder (FSAD) is a common issue causing physical and psychological pain, but it has no standard diagnostic criteria or treatment. So its pathogenesis desiderates to be explored.AimTo investigate the specific function of miR-122-5p in FSAD.Methods18 subjects were grouped into FSAD and normal control groups according to the Chinese version of the Female Sexual Function Index, and the expression levels of miR-122-5p and vasoactive intestinal peptide receptor 1 (VIPR1) protein in their tissue were verified through real-time quantitative polymerase chain reaction (qRT-PCR) and western blot (WB) analysis. Then in vitro experiment, miR-122-5p was overexpressed or inhibited in rat vaginal smooth muscle cells (SMCs). The relaxation of rat vaginal SMCs was reflected by the cell morphology, intracellular free cytosolic calcium ion (Ca2+) levels, cell proliferation and apoptosis, together with the cyclic adenosine monophosphate (cAMP) concentration and protein kinase A (PKA) activities. Additionally, the expression levels of relaxation-related proteins, including VIPR1, stimulatory G protein (Gs), adenylate cyclase (AC), and PKA, were detected based on WB analysis. Furthermore, a rescue experiment that simultaneously overexpressed or silenced miR-122-5p and VIPR1 was conducted, and all the indicators were evaluated.Main Outcomes MeasureThe expression level of VIPR1 and downstream proteins, cell morphology, cell proliferation and apoptosis, and intracellular free Ca2+ levels were examined.ResultsWe verified that women with FSAD had higher miR-122-5p and lower VIPR1 protein. Then overexpressing miR-122-5p decreased relaxation of rat vaginal SMCs, which was manifested as a contractile morphology of cells, an increased intracellular free Ca2+ concentration, and lower cAMP concentration and PKA activity. Moreover, by rescue experiments, we inferred that VIPR1 was the target of miR-122-5p and affected the relaxation function of vaginal SMCs.ConclusionmiR-122-5p regulates the relaxation of vaginal SMCs in FSAD by targeting VIPR1, ulteriorly providing an underlying diagnostic and therapeutic target for FSAD.Cong S, Gui T, Shi Q, et al. Overexpressing miR-122-5p Inhibits the Relaxation of Vaginal Smooth Muscle in Female Sexual Arousal Disorder by Targeting Vasoactive Intestinal Peptide Receptor 1. Sex Med 2021;9:100390.

Altered mechanics of vaginal smooth muscle cells due to the lysyl oxidase-like1 knockout

The remodeling mechanisms that cause connective tissue of the vaginal wall, consisting mostly of smooth muscle, to weaken after vaginal delivery are not fully understood. Abnormal remodeling after delivery can contribute to development of pelvic organ prolapse and other pelvic floor disorders.The present study used vaginal smooth muscle cells (vSMCs) isolated from knockout mice lacking the expression of the lysyl oxidase-like1 (LOXL1) enzyme, a well-characterized animal model for pelvic organ prolapse. We tested if vaginal smooth muscle cells from LOXL1 knockout mice have altered mechanics including stiffness and surface adhesion.Using atomic force microscopy, we performed nanoindentations on both isolated and confluent cells to evaluate the effect of LOXL1 knockout on in vitro cultures of vSMCs cells from nulliparous mice. The results show that LOXL1 knockout vSMCs have increased stiffness in pre-confluent but decreased stiffness in confluent cultures (p* < 0.05) and significant decreased surface adhesion in pre-confluent cultures (p* < 0.05). This study provides evidence that the weakening of vaginal connective tissue in the absense of LOXL1 changes the mechanical properties of the vSMCs. Statement of significancePelvic organ prolapse is a common condition affecting millions of women worldwide, which significantly impacts their quality of life. Alterations in vaginal and pelvic floor mechanical properties can change their ability to support the pelvic organs. This study provides evidence of altered stiffness of vaginal smooth muscle cells from mice resembling pelvic organ prolapse. The results from this study set a foundation to develop pathophysiology–driven therapies focused on the interplay between smooth muscle mechanics and extracellular matrix remodeling.

009 Immunomodulatory Effects of Dihydrotestosterone (DHT) in Human Vaginal Smooth Muscle Cells

009 Immunomodulatory Effects of Dihydrotestosterone (DHT) in Human Vaginal Smooth Muscle Cells

037 Immunomodulatory Effects of Dihydrotestosterone (DHT) in Rat Vaginal Smooth Muscle Cells

037 Immunomodulatory Effects of Dihydrotestosterone (DHT) in Rat Vaginal Smooth Muscle Cells

Study of the anti-inflammatory effects of dihydrotestosterone in human vaginal smooth muscle cells

Study of the anti-inflammatory effects of dihydrotestosterone in human vaginal smooth muscle cells

Immunomodulatory effects of dihydrotestosterone (DHT) in rat vaginal smooth muscle cells

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

PS-04-006 Immunomodulatory effects of Dihydrotestosterone (DHT) in rat vaginal smooth muscle cells

Androgens, in particular Dihydrotestosterone (DHT), show immunomodulatory protective effects in experimental models of chronic inflammation. We aimed to evaluate the possible immunomodulatory effects of DHT in smooth muscle cells (SMCs) isolated from vagina of mature intact Sprague-Dawley rats. SMCs derived from distal vagina were isolated and characterized with α-smooth muscle actin (a-SMA) and myosin heavy chain 11 (MHCII). Then they were left untreated (control) or treated in vitro with different stimuli: Lipopolysaccharides (LPS; 100 ng/ml), the strongest immunogenic ligand for TLR; DHT (30nM); and DHT+LPS (30nM, 100ng/ml) for 24 hours. With Real-Time Quantitative Reverse Transcriptase Polymerase Chain Reaction, we evaluated mRNA expression of the main pro-inflammatory markers: interleukin-6 (IL-6), IL-1b, chemokine (C-X-C motif) ligand (1CXCL1), cyclooxygenase-2 (COX-2), CD4, RAR-related orphan receptor C (RORC), chemokine for recruitment of macrophages [monocyte chemotactic protein 1 (MCP1) and membrane receptors which mediate the cell inflammatory response, such as Toll-Like Receptors (TLRs). In addition, immunofluorescence studies were performed to analyze the nuclear translocation of NF-kB, an important transcriptional mediator of the inflammatory response.

PS-04-008 Study of the anti-inflammatory effects of dihydrotestosterone in human vaginal smooth muscle cells

PS-04-008 Study of the anti-inflammatory effects of dihydrotestosterone in human vaginal smooth muscle cells

The Effects of Heat Exposure on Vaginal Smooth Muscle Cells: Elastin and Collagen Production

Aims: To evaluate smooth muscle cells (SMCs) proliferation and elastin and collagen production after heat exposure (65°C). Methods: Samples were taken from the anterior vaginal wall, SMCs were cultured, and heated to 65°C for 30 and 60 s. Cell proliferation was assessed; tropoelastin and collagen production was measured. Results: Heat does not affect SMC proliferation at 65°C neither at 30 nor at 60 s. Surface-deposited elastin level was significantly increased after heat exposure (mean ± SD, 30 s 155 ± 5% of control [p < 0.01] and 60 s 516 ± 40% of control [p < 0.01]). Tropoelastin levels in the culture media were significantly lower after 60 s of heat exposure (mean ± SD, 30 s 102 ± 5% of control [p = ns] and 60 s 70 ± 2% of control [p = 0.04]). Significant increase in surface-deposited collagen production was found (mean ± SD, 30 s 170 ± 6% of control [p < 0.01] and 60 s 123 ± 6% of control [p < 0.01]), but no such elevation was measured in the media after heat exposure (mean ± SD, 30 s 120 ± 20% of control [p = ns] and 60 s 100 ± 20% of control [p = ns]). Conclusion: When SMCs are exposed to heat there is significant elevation in collagen and elastin production. Changes in the composition of the extracellular matrix after heat exposure may contribute to vaginal wall remodeling.

124 PATHOPHYSIOLOGIC CHANGES IN LOXL-1 KNOCKOUT MOUSE WITH PELVIC FLOOR DYSFUNCTION INDUCE A COMPENSATORY AND ABERRANT ELASTIN REGENERATIVE RESPONSE BY VAGINAL SMOOTH MUSCLE CELLS

INTRODUCTION AND OBJECTIVES: Impaired elastic matrix remodeling during pregnancy and after parturition may be linked to pelvic organ prolapse (POP). In lysyl oxidase like-1 (LOXL1) knockout (KO) mice, POP develops after vaginal delivery and correlates with disorganized elastin clusters. The goal of this project was to investigate the alterations in new elastic matrix assembly by vaginal smooth muscle cells (SMC) in age-matched nulliparious (N), multiparous nonprolapsed (MNP) and multiparous prolapsed (MP) LOXL1 KO mice. METHODS: Primary vaginal SMC cultures from all LOXL1 KO mice expressed the SMC markers -actin, SM22, caldesmon, smoothelin and tropomyosin. Passage 1 SMC from each group were cultured for 21 days in DMEM/F12 medium with 10% fetal bovine serum, and then assayed for increase in DNA content, collagen matrix, and alkalisoluble, and insoluble matrix elastin. RT-PCR was used to assess expression of collagen, tropoelastin, fibrillin-1, and lysyl oxidase (LOX). Elastic matrix ultrastructure and fiber integrity was assessed using TEM. RESULTS: SMC from MP mice were smaller, less fusiform, and proliferated more rapidly than SMC from N mice. SMC from MNP mice were larger, more spread, and less proliferative than SMC from MP mice. Elastin, LOX, and collagen mRNA expression were reduced in SMC from MNP mice, and were upregulated in SMC from MP mice compared to N mice. Fibrillin mRNA levels were significantly higher in SMC from MNP mice, while LOX mRNA levels were lower in SMC from multiparous mice. SMC from MNP mice synthesized less elastic matrix per well & per cell than did SMC from MP or N mice. Elastin deposits were sporadic in cultures of SMC from MNP mice. A few aberrant fibers were seen in cultures of SMC from N mice. Such fibers were more numerous in cultures of SMC from MP mice. CONCLUSIONS: New elastic matrix synthesis by LOXL1 KO vaginal SMC diminishes with pregnancy and multi-parity. SMC from MP mice exhibit a more activated, proliferative, and remodeling phenotype than SMC from MNP or N mice. Elastic fiber assembly by MNP LOXL1 KO mice is not compromised by reduced fibrillin deposition, but by poor crosslinking from reduced LOX mRNA and the lack of LOXL1. Reduced elastic matrix regenerative repair due to suppression of elastin mRNA by SMC in MNP mice may lead to POP. Pathophysiologic changes in LOXL1 KO mice induce a compensatory and aberrant elastin regenerative response by vaginal SMC. Therapies to regenerate healthy matrix may have application to POP.

Bone Morphogenetic Protein 4 Mediates Estrogen-Regulated Sensory Axon Plasticity in the Adult Female Reproductive Tract

Peripheral axons are structurally plastic even in the adult, and altered axon density is implicated in many disorders and pain syndromes. However, mechanisms responsible for peripheral axon remodeling are poorly understood. Physiological plasticity is characteristic of the female reproductive tract: vaginal sensory innervation density is low under high estrogen conditions, such as term pregnancy, whereas density is high in low-estrogen conditions, such as menopause. We exploited this system in rats to identify factors responsible for adult peripheral neuroplasticity. Calcitonin gene-related peptide-immunoreactive sensory innervation is distributed primarily within the vaginal submucosa. Submucosal smooth muscle cells express bone morphogenetic protein 4 (BMP4). With low estrogen, BMP4 expression was elevated, indicating negative regulation by this hormone. Vaginal smooth muscle cells induced robust neurite outgrowth by cocultured dorsal root ganglion neurons, which was prevented by neutralizing BMP4 with noggin or anti-BMP4. Estrogen also prevented axon outgrowth, and this was reversed by exogenous BMP4. Nuclear accumulation of phosphorylated Smad1, a primary transcription factor for BMP4 signaling, was high in vagina-projecting sensory neurons after ovariectomy and reduced by estrogen. BMP4 regulation of innervation was confirmed in vivo using lentiviral transduction to overexpress BMP4 in an estrogen-independent manner. Submucosal regions with high virally induced BMP4 expression had high innervation density despite elevated estrogen. These findings show that BMP4, an important factor in early nervous system development and regeneration after injury, is a critical mediator of adult physiological plasticity as well. Altered BMP4 expression may therefore contribute to sensory hyperinnervation, a hallmark of several pain disorders, including vulvodynia.

Bladder acellular matrix seeding with autologous cultured vaginal smooth cells repaired rabbit vaginal defect

Objective To evaluate the feasibility of bladder extracellular matrix (BACM) seeding with autologous cultured vaginal smooth muscle cells (VSMC) repaired rabbit vaginal defect.Methods This study included 24 female rabbits.BACM and vaginal acellular matrix (VACM) were obtained from 8 rabbits by decellularization process.The other 16 rabbits were randomly divided into experimental and control groups.Vaginal tissue biopsies ( ～ 1 cm2) were harvested from female New Zealand rabbits.VSMC were cultured and stained with a-smooth muscle actin antibodies. Cultured VSMC cells were seeded on BACM ( experimental group) or VACM ( control group) at a cell density of 1 × 107 cells/cm2.The cell-seeded matrixes were cultured for 5days.In experimental group of 8 rabbits,a 2 cm segment of vagina was resected and replaced with BACM seeding with VSMC.Then the regenerative segment was studied with histological technique by hematoxylin-eosin staining after 3,6 and 12 weeks postoperative aud vaginography was performed at 12 weeks postoperative.The 8 rabbits in control group underwent the exact same procedure as above but the vaginal defect was repaired with VACM seeding with VSMC,Results The prepared BACM and VACM were transparent,HE staining and scanning electron microscopy showed the two acellular matrix was both consisted of abundant network of fibers with the regular arrangement,without cellular debris.Primary culture of VSMC was successfully established and passaged,and was uniformly spindle-shaped in the confluent state and showed a characteristic hill and valley'formation.Immunohistochemical staining showed VSMC in culture stained positively with a-smooth muscle actin antibodies.VSMC began to adhere to the BACM 5 hour after implanting and the number of the adhered cells increased with time.Cells gradually expanded and showed the typical morphology of smooth muscle cells.Three weeks after implantation in vivo,the luminal surface of matrix was completely covered by vaginal epithelial tissue,a layer of smooth muscle cells was formed in the outer surface of the matrix.Multilayered vaginal epithelial and improved development of organized muscle bundles was observed after 6 weeks.The regenerative tissue was equivalent to the normal vaginal tissue at 12 weeks postoperatively.Vaginography demonstrated the maintenance of full patency and a wide vaginal caliber without fibrosis and graft rejection.There was no significant difference in all evaluated items between experimental and control groups.Conclusions BACM has the same regenerative process as VACM in the replacement of vaginal defect.Moreover,BACM has wider source and appears to be an suitable material for vaginal replacement. Key words: Urinary bladder; Extracellular matrix; Vagina/cytology; Myocytes, smooth muscle; Vagina/abnormalities; Rabbits

Estrogen inhibits vaginal tropoelastin and TGF-β1 production

The aim of this study was to quantify the effects of estrogen on vaginal smooth muscle cell (SMC) tropoelastin and transforming growth factor (TGF)-β1 production. Primary SMC were incubated with estradiol, and cell proliferation was assessed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay at 48 h. Supernatants were collected and tropoelastin and TGF-β1 levels measured. SMC proliferation was significantly increased by estradiol [relative cell number, mean ± standard error (SE), estradiol 0.1 μM 116 ± 19 % of control (P = NS), 1 μM 127 ± 13 % of control (P < 0.05), 10 μM 153 ± 26 % of control, (P < 0.05)]. Tropoelastin production was significantly decreased by estrogen [mean ± SE, estradiol 0.1 μM 78 ± 2 % of control (P < 0.05), 1 μM 76 ± 4 % of control (P < 0.05), 10 μM 67 ± 3 % of control, (P < 0.05)]. In addition, TGF-β1 production was significantly decreased [mean ± SE, estradiol 0.1 μM 96 ± 4 % of control (P = NS), 1 μM 84 ± 6 % of control (P < 0.05), 10 μM 70 ± 6 % of control, (P < 0.05)]. Estrogen increases vaginal SMC proliferation and inhibits tropoelastin and TGF-β1 production.

Effects of PPAR-delta agonist and zinc on vaginal smooth muscle cells collagen and tropoelastin production

The objective was to measure the effects of peroxisome proliferator-activated receptor delta (PPAR-delta) agonist and zinc sulfate (ZS) on vaginal smooth muscle cell (SMC) proliferation, tropoelastin production, and collagen production. SMC cultures were performed from vaginal wall biopsies and were incubated with ZS and PPAR-delta agonist GW501516 (GW). Cell proliferation was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Supernatants and cell lysates were collected. Tropoelastin production was measured by Fastin Elastin Assay and collagen was measured with Sircol Collagen Assay. SMC proliferation was similar with 20 μM ZS or 10 nM GW compared to control. Tropoelastin production was significantly increased by 20 μM ZS and by 10 nM GW. Cell culture surface deposited elastin production was significantly increased by 20 μM ZS and by the combination of 20 μM ZS with 10 nM GW, and collagen production was significantly increased by 10 nM GW and by the combination of 20 μM ZS with 10 nM GW. PPAR-delta agonist and ZS increases vaginal SMC tropoelastin and collagen production.

Induced Regenerative Elastic Matrix Repair in LOXL1 Knockout Mouse Cell Cultures: Towards Potential therapy for Pelvic Organ Prolapse.

Impaired elastic matrix remodeling occurs in reproductive tissues after vaginal delivery. This has been linked to development of pelvic organ prolapse (POP) for which there currently is no pharmacologic therapy. Hyaluronan oligomers and transforming growth factor beta 1 (termed elastogenic factors, EFs) have been shown to significantly enhance tropoelastin synthesis, elastic fiber assembly, and crosslinking by adult vascular smooth muscle cells (SMCs). The goal of this study was to ascertain if these factors similarly improve the quantity and quality of elastic matrix deposition by vaginal SMCs (VSMCs) isolated from lysyl oxidase like-1 knock out (LOXL1 KO) mouse model of POP. Cells isolated from whole vagina of a LOXL1 KO mouse (multiparous, stage 3 prolapse) were cultured and identified as SMCs by their expression of various SMC markers. Passage 2 vaginal SMCs (VSMCs; 3×104/10 cm2) were cultured for 21 days with EFs. Cell layers and spent medium aliquots were assessed for elastin content and quality. EF-treated VSMCs proliferated at a similar rate to untreated controls but synthesized more total elastin primarily in the form of soluble matrix elastin. Elastin mRNA was also increased compared to controls. The elastic matrix was significantly denser in EF-treated cultures, which was composed of more mature, non-interrupted elastic fibers that were absent in controls. The results are promising towards development of a therapy to enhance regenerative elastic matrix repair in post-partum female pelvic floor tissues.

TGF-beta 1 is a potential regulator of vaginal tropoelastin production

Our aims were to correlate transforming growth factor (TGF)-β1 and elastin mRNA expression in the vagina of women and to measure the effects of TGF-β1 on vaginal smooth muscle cell (SMC) proliferation and tropoelastin production. Vaginal walls were sampled in women (n = 20). TGF-β1 and elastin mRNA expression was assessed by RT-PCR. SMC cultures were performed from vaginal wall biopsies. SMC were incubated with TGF-β1, and cell proliferation was assessed by MTT-assay. Tropoelastin production was measured by the Fastin Elastin Assay. There was a significant positive correlation between TGF-β1 and elastin mRNA (r = 0.784, P < 0.01). SMC proliferation was significantly increased by 10 ng/mL TGF-β1 [relative cell number, mean ± SD, 198% ± 32% of control (P = 0.01)]. Tropoelastin production was significantly increased by TGF-β1 [mean ± SD, 645% ± 180% of control (P = 0.01)]. There is a positive correlation between TGF-β1 and elastin mRNA expression in the vaginal wall. In vitro, TGF-β1 increases vaginal tropoelastin production in vaginal SMC.

The effect of biological and synthetic meshes on vaginal smooth muscle cell proliferation

To compare the effects of polypropylene mesh or porcine dermal acellular collagen matrix mesh with and without estradiol supplementation on vaginal smooth muscle cells (VaSMC) proliferation. Under in vitro culture conditions, VaSMC proliferation was significantly higher in the porcine dermal acellular collagen matrix mesh exposed cells compared to the type I polypropylene mesh exposed cells (relative cell number, mean ± SD, 0.27 ± 0.03 vs. 0.21 ± 0.01, P = 0.03). Under estradiol supplementation cell proliferation in the porcine mesh exposed cells remained significantly higher compared to the polypropylene mesh exposed cells (relative cell number, mean ± SD, 0.27 ± 0.04 vs. 0.15 ± 0.03, P < 0.01). The decreased rate of erosion found with the utilization of biological absorbable mesh in vaginal reconstructive surgery may partially be explained by the significantly increased VaSMC proliferation with porcine dermal acellular collagen mesh compared to polypropylene mesh.