Extracellular matrix components and elasticity regulate mouse vaginal epithelial differentiation induced by mesenchymal cells†.

Oviduct, uterus, and vagina are derived from Müllerian ducts. But only in the vagina, the epithelium differentiates into stratified layers. Organ-specific secreted factors derived from the stroma of a neonatal mouse induce epithelial differentiation in the female reproductive tracts. However, the effects of the components and mechanical property of extracellular matrix (ECM) on the regulation of gene expression in the mesenchymal cells of neonatal stroma and differentiation of epithelium in the female reproductive tracts have been overlooked. In the present study, we have developed a simple 3D neonatal vaginal model using clonal cell lines to study the effect of ECM's components and stiffness on the epithelial stratification. Transcriptome analysis was performed by DNA-microarray to identify the components of ECM involved in the differentiation of vaginal epithelial stratification. The knockdown experiment of the candidate genes relating to vaginal epithelial stratification was focused on fibromodulin (Fmod), a collagen cross-linking protein. FMOD was essential for the expression of Bmp4, which encodes secreted factors to induce the epithelial stratification of vaginal mesenchymal cells. Furthermore, stiffer ECM as a scaffold for epithelial cells is necessary for vaginal epithelial stratification. Therefore, the components and stiffness of ECM are both crucial for the epithelial stratification in the neonatal vagina.

The development of the human vaginal fornix and the portio cervicis.

INTRODUCTION: One of the transitional zones of the human body is situated in the cervix uteri. The developmental differentiation of epithelial and stromal characteristics in such a region is of high clinical interest. However, few studies have focused on the development of this region, and information in anatomical and clinical textbooks is limited. We therefore examined the development of the human vaginal fornix and the cervix uteri during prenatal development. MATERIALS AND METHODS: We examined 29 female embryos and fetuses between 20 and 34 weeks and two newborns using histology and immunohistochemistry. RESULTS: The characteristic shape of the portiocervicis and the vaginal fornix first became visible in mid-term fetuses because of the different muscular coats and of an uncategorized Müllerian-derived epithelium, which was rapidly replaced by a multilayered squamous epithelium. Only thereafter, in older fetuses, were there organogenetic differentiation of the epithelia and the underlying stroma of the cervical canal. UGS-derived p63/CK17-positive cells could be identified as precursor cells for the squamous epithelium, and Müllerian-derived CK7-positive cells for the columnar-type epithelium. Both cell types and different stromal zones were already present in a prenatal transformation zone. Initial functional differentiation could be observed in perinatal stages. CONCLUSIONS: Our results on prenatal human development strongly support the view that two different cell lineages meet at the transitional zone of the cervix uteri and that these lineages depend on alternative signals from the underlying stromal compartment.

Primary Amenorrhea Due to Anatomical Abnormalities of the Reproductive Tract: Molecular Insight.

Congenital anomalies of the female reproductive tract that present with primary amenorrhea involve Müllerian aplasia, also known as Mayer-Rokitansky-Küster-Hauser syndrome (MRKHS), and cervical and vaginal anomalies that completely obstruct the reproductive tract. Karyotype abnormalities do not exclude the diagnosis of MRKHS. Familial cases of Müllerian anomalies and associated malformations of the urinary and skeletal systems strongly suggest a complex genetic etiology, but so far, the molecular mechanism in the vast majority of cases remains unknown. Primary amenorrhea may also be the first presentation of complete androgen insensitivity syndrome, steroid 5α-reductase type 2 deficiency, 17ß-hydroxysteroid dehydrogenase type 3 deficiency, and Leydig cells hypoplasia type 1; therefore, these disorders should be considered in the differential diagnosis of the congenital absence of the uterus and vagina. The molecular diagnosis in the majority of these cases can be established.

Spatiotemporal dynamics of androgen signaling underlie sexual differentiation and congenital malformations of the urethra and vagina.

Disorders of sex development (DSDs) are congenital anomalies that affect sexual differentiation of genitourinary organs and secondary sex characters. A common cause of female genital virilization is congenital adrenal hyperplasia (CAH), in which excess androgen production during development of 46XX females can result in vaginal atresia, masculinization of the urethra, a single urogenital sinus, and clitoral hypertrophy or ambiguous external genitalia. Development of the vagina depends on sexual differentiation of the urogenital sinus ridge, an epithelial thickening that forms where the sex ducts attach to the anterior urethra. In females, the sinus ridge descends posteriorly to allow the vaginal opening to form in the vulva, whereas in males and in females with CAH, androgens inhibit descent of the sinus ridge. The mechanisms that regulate development of the female urethra and vagina are largely unknown. Here we show that the timing and duration of, and the cell population targeted by, androgen signaling determine the position of vaginal attachment to the urethra. Manipulations of androgen signaling in utero reveal a temporal window of development when sinus ridge fate is determined. Cell type-specific genetic deletions of androgen receptor (Ar) identify a subpopulation of mesenchymal cells that regulate sinus ridge morphogenesis. These results reveal a common mechanism that coordinates development of the vagina and feminization of the urethra, which may account for development of a single urogenital sinus in females exposed to excessive androgen during a critical period of prenatal development.

Retinoic acid signaling determines the fate of uterine stroma in the mouse Müllerian duct.

The Müllerian duct develops into the oviduct, uterus, and vagina, all of which are quite distinct in their morphology and function. The epithelial fate of these female reproductive organs in developing mice is determined by factors secreted from the stroma; however, how stromal differentiation occurs in the female reproductive organs derived from the Müllerian duct is still unclear. In the present study, roles of retinoic acid (RA) signaling in developing female reproductive tracts were investigated. Retinol dehydrogenase 10 (RDH10) and aldehyde dehydrogenase family 1 subfamily A2 (ALDH1A2) mRNAs and proteins and transactivation activity of endogenous RA were found in the stroma of proximal Müllerian ducts and gradually decreased from the proximal to caudal regions in fetal mice. In organ-cultured Müllerian ducts, retinaldehyde or RA treatment induced uterine epithelial differentiation, defined as a layer of columnar epithelial cells negative for oviductal and vaginal epithelial markers. In contrast, inhibition of RA receptor (RAR) signaling induced vaginal epithelial differentiation, characterized as vaginal epithelial marker genes-positive stratified epithelium. Grafting experiments of the organ-cultured Müllerian duct revealed irreversible epithelial fate determination. Although RAR did not directly bind to the homeobox A10 (Hoxa10) promoter region, RA-RAR signaling stimulated Hoxa10 expression. Thus, RA-RAR signaling in the Müllerian duct determines the fate of stroma to form the future uterus and vagina.

Peculiarities of prenatal vagina morphogenesis.

OBJECTIVE: Introduction: The rapid development of perinatal gynecology requires from the anatomists comprehensive studies of the patterns of prenatal morphogenesis and the development of topographic and anatomical relationships of female reproductive organs in the human fetuses of different age groups. The aim: To study the development and formation of the vaginal topography in the prenatal period of human ontogenesis. PATIENTS AND METHODS: Materials and methods: The study has been conducted based on 23 series of histological and topographic-anatomical sections of human prefetuses aged 9-12 weeks with 31.0-80.0 mm of crown-rump length (CRL) and 83 specimens of female human fetuses aged 4-9 months with 81.0-345.0 mm of CRL by means of a complex of adequate morphological methods of investigation. RESULTS: Results and conclusions: Vaginal formation occurs during the 9th week of embryogenesis (prefetuses of 31.0-41.0 mm of CRL) due to the fusion of two different embryonic structures: mesodermal paramesonephral ducts and endodermal urogenital sinus. In this case, the caudal regions of the paramesonephral ducts are transformed into the uterus and the superior two thirds of the vagina, and the inferior third of the vagina develops from the urogenital sinus. Common uterovaginal canal, divided into right and left cavities by mesenchymal septum, is formed in the female prefetuses of 38.0-43.0 mm of CRL due to the fusion of the caudal regions of the paramesonephral ducts in the area of the posterior wall of the urogenital sinus. Complete dissolving of the septum of the uterovaginal canal occurs in prefetuses of 55.0-58.0 mm of CRL. The anterior and posterior vaginal vaults of the same depth are formed in 5-month-old fetuses. Canalization of vagina in the caudo-cranial direction is observed in the fetuses of 170.0-185.0 mm of CRL, with no clear boundary between the uterovaginal canal and the urogenital sinus. The vaginal epithelium in the upper third part originates from the uterovaginal canal, and in the lower two thirds of the vagina - from the urogenital sinus. In the 6-month-old fetuses there was detected the variability of the shape of the superior, middle and inferior third of the vagina, namely: oval (5 cases), elongated-oval (2 cases), stellate (1 case); in the lower third, the H-shaped form was predominantly found (6 fetuses). The proliferation of the hymen membrane occurs in fetuses of 220.0-245.0 mm of CRL. The absence of timely proliferation of the hymen membrane can lead to its atresia, and its premature proliferation causes the appearance of transverse vaginal septa.

The vaginal vestibule: assessing the case for an anterior and posterior division.

The vaginal vestibule has not been the subject of a dedicated journal article. Recent terminology has suggested its division into anterior and posterior components. The case for this division has not yet been assessed. Both components extend laterally from the hymen to the junction with the labia minora. The posterior vaginal vestibule is proposed to extend from the posterior aspect of the hymen to the anterior edge of the perineum whilst the anterior vestibule extends from the posterior aspect of the hymen to just below the clitoris. Anatomical considerations (differing layers) might firstly support the above division. The posterior vestibule, by necessity, is far more flexible with the superficial aspect (approximately 1.5 cm), anatomically and histologically, comprising skin and subcutaneous tissue, with perineal musculature deep to this. In turn, it is more likely to be subject to obstetric and surgical considerations than the anterior vaginal vestibule. Obstetric trauma, in particular, would tend to create defects, particularly at its posterior margin. Many dermatological and microbiological considerations may be common to both anterior and posterior vestibule. Any dermatological condition of the vestibule can result in sexual dysfunction and can be complicated by secondary muscular spasm. Congenital anomalies will differ anteriorly and posteriorly. Multiple considerations can be identified to support the case for division of the vaginal vestibule into anterior and posterior components. Neurourol. Urodynam. 36:979-983, 2017. © 2016 Wiley Periodicals, Inc.

Diethylstilbestrol induces vaginal adenosis by disrupting SMAD/RUNX1-mediated cell fate decision in the Müllerian duct epithelium.

Women exposed to diethylstilbestrol (DES) in utero frequently develop vaginal adenosis, from which clear cell adenocarcinoma can arise. Despite decades of extensive investigation, the molecular pathogenesis of DES-associated vaginal adenosis remains elusive. Here we report that DES induces vaginal adenosis by inhibiting the BMP4/Activin A-regulated vaginal cell fate decision through a downregulation of RUNX1. BMP4 and Activin A produced by vaginal mesenchyme synergistically activated the expression of ΔNp63, thus deciding vaginal epithelial cell fate in the Müllerian duct epithelial cells (MDECs) via direct binding of SMADs on the highly conserved 5' sequence of ΔNp63. Therefore, mice in which Smad4 was deleted in MDECs failed to express ΔNp63 in vaginal epithelium and developed adenosis. This SMAD-dependent ΔNp63 activation required RUNX1, a binding partner of SMADs. Conditional deletion of Runx1 in the MDECs induced adenosis in the cranial portion of vagina, which mimicked the effect of developmental DES-exposure. Furthermore, neonatal DES exposure downregulated RUNX1 in the fornix of the vagina, where DES-associated adenosis is frequently found. This observation strongly suggests that the downregulation of RUNX1 is the cause of vaginal adenosis. However, once cell fate was determined, the BMP/Activin-SMAD/RUNX1 signaling pathway became dispensable for the maintenance of ΔNp63 expression in vaginal epithelium. Instead, the activity of the ΔNp63 locus in vaginal epithelium was maintained by a ΔNp63-dependent mechanism. This is the first demonstration of a molecular mechanism through which developmental chemical exposure causes precancerous lesions by altering cell fate.

The developmental origin of cervical and vaginal epithelium and their clinical consequences: a systematic review.

OBJECTIVE: Studies on the development of the embryological and fetal development of the cervix and the vagina are rare and mostly go back to the first decades of the last century. The aims of this review were to present the latest knowledge concerning the developmental origin of cervical and vaginal epithelium and to point out new results in the context of different clinical findings. MATERIALS AND METHODS: Relevant studies published between 1910 and 2013 were identified via PubMed, MEDLINE, OVID, Web of Science, and EMBASE. The reference lists of retrieved articles were reviewed to locate additional articles. Each abstract was reviewed, and the appropriate publications were obtained and reviewed as well. A total of 33 articles and 8 book chapters were selected for citation in this review. RESULTS: New objective findings clearly show that human prenatal epithelialization of the cervix and vagina results in 3 morphogenetically determined units: (i) the Müllerian columnar epithelium of the endocervix, (ii) the Müllerian squamous epithelium of the ectocervix and the upper vagina, and (iii) the vaginal squamous epithelium of the lower vagina. CONCLUSIONS: These results are of high clinical relevance and may provide new insight into the histogenesis of ectopy, vaginal adenosis, and the congenital transformation zone. They should be added to the explanations in gynecological, colposcopical, and gynecopathological textbooks.

Development of epithelial and mesenchymal regionalization of the human fetal utero-vaginal anlagen.

Literature on the development of the human vagina is abundant; however, contributions concerning the prenatal development of the entire utero-vaginal anlagen (UVA) are rare or carried out in rodents. The primary epithelial characteristics in the adult vagina and uterus are determined during prenatal development and depend on epithelio-mesenchymal stroma interaction; thus an investigation summarizing the spatiotemporal distribution of relevant molecular markers in the entire human UVA will be of current interest. We phenotyped epithelial and mesenchymal characteristics in sagittal sections from 24 female fetuses of 14-34 weeks of gestation and two female newborns by immunostaining with cytokeratins 8, 13, 14 and 17, p63, bcl-2, bmp4, HOX A13, CD31, VEGF, SMA, Pax2 and vimentin. Epithelial differentiation followed a caudal-to-cranial direction in the UVA. Due to the cytokeratin profile of cytokeratins 8, 13 and 14, the characteristics of the different epithelial zones in the UVA could already be recognized in middle-age fetuses. Vaginal epithelium originated from the urogenital sinus in the lower portion and initiated the transformation of vimentin-positive Müllerian epithelium in the upper vaginal portion. During prenatal development the original squamo-columnar junction was clearly detectable from week 24 onwards and was always found in the cervical canal. Early blc-2 positivity within the surrounding mesenchyme of the entire vagina including the portio region pointed to an organ-specific mesenchymal influence. Prenatal findings in human specimens clearly show that fornix epithelium up to the squamo-columnar junction is of vaginal Müllerian origin, and the cervical epithelium cranial to the squamo-columnar junction is of uterine Müllerian origin and includes cells with enough plasticity to transform into squamous epithelium.

Pelvic exenteration for recurrent squamous cell carcinoma of the pelvic organs arising from the cloaca--a single institution's experience over 16 years.

AIM: Minimal data are available on the role of pelvic exenteration in patients with recurrent squamous cell carcinoma (SCC) of the pelvic organs. This study aimed to highlight our experience of pelvic exenteration in patients with recurrent and re-recurrent SCC of the pelvic organs. METHOD: A retrospective review of all patients who underwent pelvic exenteration for recurrent SCC of the pelvic organs arising from the embryological cloaca from 1994 to 2010 was performed. RESULTS: Twenty-four patients (median age 59, range, 27-79 years) underwent pelvic exenteration for recurrent SCC of the anus (18), cervix and upper vagina (2), lower vagina (1) and the vulva (3). Nine patients with anal SCC had undergone abdominoperineal excision prior to pelvic exenteration. Ten (41.7%) patients underwent a complete pelvic exenteration procedure, while sacrectomy was performed in 13 (54.2%) patients. There was no 30-day inpatient mortality. An R0 resection was achieved in 15 (62.5%) patients. Three (12.5%) had R1 resections while 6 (25%) had R2 resections. In the 15 patients with an R0 resection, 7 (46.7%) developed metastatic disease at a median of 18 (range 10-131) months. After a median follow-up of 26 (range 4-169) months, 1- and 2-year overall survival rates were 64% [95% confidence interval (CI), 44-84%] and 57% (95% CI 35-79%), respectively. CONCLUSION: Pelvic exenteration for recurrent SCC of the cloaca is safe and feasible even after previous salvage surgery. An R0 resection can be achieved in 62.5% of the patients with reasonable early survival though less than published recurrent rectal cancer studies.

The vagina as a route for drug delivery: a review.

Overactive bladder (OAB) syndrome has a significant deleterious impact on quality of life. After conservative therapy and bladder retaining, antimuscarinic drugs remain the mainstay of OAB management. Oral therapy is associated with frequent side effects, leading to the development of alternative agents and formulations or the use of novel routes of drug administration, such as the vaginal route. The vagina is often ideal for drug delivery because it allows the use of lower doses, maintains steady drug administration levels, and requires less frequent administration than the oral route. With vaginal drug administration, absorption is unaffected by gastrointestinal disturbances, there is no first-pass effect, and use is discreet. The aim of this review is to provide a background overview of vaginal development, anatomy, and physiology and the effect this has on the use of this route for both local and systemic drug delivery, with special reference to OAB management. Vaginal therapy continues to be an underused route of drug delivery. Vaginal administration allows nondaily, low, continuous dosing, which results in stable drug levels and may, in turn, achieve a lower incidence of side effects and improve patient compliance. These benefits must be balanced against inherent patient or physician bias against using this route and the need to overcome cultural, personal, and hygiene-related barriers to this form of therapy. More sophisticated and programmable vaginal rings are being developed for systemic delivery of therapeutically important macromolecules, such as antimuscarinic therapy in OAB management.

Molecular characteristics and alterations during early development of the human vagina.

Unresolved questions remain concerning the derivation of the vagina with respect to the relative contributions from the Müllerian ducts, the urogenital sinus, and the Wolffian ducts. Recent molecular and cellular studies in rodents have opened up a large gap between the level of understanding of vaginal development in mice and understanding of human vaginal development, which is based on histology. To compare the findings in mice with human vaginal development and to address this gap, we analysed molecular characteristics of the urogenital sinus, Wolffian ducts, and Müllerian ducts in 8-14-week-old human specimens using immunohistochemical methods. The monoclonal antibodies used were directed against cytokeratin (CK) 14, CK19, vimentin, laminin, p63, E-cadherin, caspase-3, Ki67, HOX A13, and BMP-4. The immunohistochemical analysis revealed that, during weeks 8-9, the epithelium of the Müllerian ducts became positive for p63 as p63-positive cells that originated from the sinus epithelium reached the caudal tip of the fused Müllerian ducts via the Wolffian ducts. The lumen of the fused Müllerian ducts was closed by an epithelial plug that contained both vimentin-positive and vimentin-negative cells. Subsequently, the resulting epithelial tube enlarged by proliferation of basal p63-positive cells. The first signs of squamous differentiation were detected during week 14, with the appearance of CK14-positive cells. According to our results, all three components, namely, the urogenital sinus, Wolffian ducts, and Müllerian ducts, interacted during the formation of the human vagina. The sinus epithelium provided p63-positive cells, the Wollfian ducts acted as a 'transporter', and the Müllerian ducts contributed the guiding structure for the vaginal anlagen. Epithelial differentiation began at the end of the period studied and extended in a caudo-cranial direction. The present study is one of the first to provide up-to-date molecular correlates for human vaginal development that can be compared with the results of cell biological studies in rodents.

Normal and abnormal epithelial differentiation in the female reproductive tract.

In mammals, the female reproductive tract (FRT) develops from a pair of paramesonephric or Müllerian ducts (MDs), which arise from coelomic epithelial cells of mesodermal origin. During development, the MDs undergo a dynamic morphogenetic transformation from simple tubes consisting of homogeneous epithelium and surrounding mesenchyme into several distinct organs namely the oviduct, uterus, cervix and vagina. Following the formation of anatomically distinctive organs, the uniform MD epithelium (MDE) differentiates into diverse epithelial cell types with unique morphology and functions in each organ. Classic tissue recombination studies, in which the epithelium and mesenchyme isolated from the newborn mouse FRT were recombined, have established that the organ specific epithelial cell fate of MDE is dictated by the underlying mesenchyme. The tissue recombination studies have also demonstrated that there is a narrow developmental window for the epithelial cell fate determination in MD-derived organs. Accordingly, the developmental plasticity of epithelial cells is mostly lost in mature FRT. If the signaling that controls epithelial differentiation is disrupted at the critical developmental stage, the cell fate of MD-derived epithelial tissues will be permanently altered and can result in epithelial lesions in adult life. A disruption of signaling that maintains epithelial cell fate can also cause epithelial lesions in the FRT. In this review, the pathogenesis of cervical/vaginal adenoses and uterine squamous metaplasia is discussed as examples of such incidences.

Fetal hydrometrocolpos, uterus didelphys with low vaginal and anal atresia: difficulties in differentiation from a complex cloacal malformation: a case report.

Hydrometrocolpos, occurring in approximately 1/6000 newborn girls, can be caused by a stenotic urogenital sinus, a severe cloacal malformation, but also by other conditions such as an imperforate hymen, a midline vaginal septum and vaginal atresia. The prenatal differential diagnosis of this wide spectrum of conditions is not easy and requires a multidisciplinary approach with follow-up scans and MRI to access the severity of the condition. A non-consanguineous couple was referred in the first pregnancy at 30 weeks. The father, 30 years of age, of Kaukasian origin, and the mother of Asian origin, 26 years of age. Ultrasound at 30 weeks revealed ambiguous genitalia (with suspicion of clitoral hypertrophy), a septated structure located behind the bladder compatible with hydrometrocolpos with a uterine malformation (uterus didelphys), a single umbilical artery, mild ascites and growth on the tenth centile. The differential diagnosis included a vaginal atresia, a urogenital sinus and a more severe cloacal malformation. After serial scans, MRI and counselling by an experienced surgeon the preferential diagnosis of a cloacal malformation was made and a late pregnancy termination was performed. Pathological examination revealed: low vaginal atresia with uterus didelphys, anal atresia with rectovaginal fistula and a normal urinary tractus. The differential diagnosis between hydrometrocolpos due to vaginal atresia or due to a more severe cloacal malformation is not straightforward. Care should be taken in decision making and counselling patients with these complex prenatal malformations.

[Mayer-Rokitansky-Küster-Hauser syndrome. A report of two cases]. / Síndrome de Mayer-Rokitansky-Küster-Hauser: reporte de dos casos y revisión de la bibliografía.

The Mayer-Rokitansky-Kuster-Hauser is a rare congenital anomaly characterized by lack of vaginal and uterine development variable and normal ovaries. It results from agenesis or hypoplasia Müller duct system. Cervicovaginal agenesis as part of the complex syndrome, is even rarer. We report two cases: adolescent patient with primary amenorrhea, cervicovaginal agenesis and chronic pelvic pain, and a 28-year-old patient with primary amenorrhea, congenital absence of uterus and vagina.

Ontogenetic anatomy of the distal vagina: relevance for local tumor spread and implications for cancer surgery.

OBJECTIVE: We have suggested to base cancer surgery on ontogenetic anatomy and the compartment theory of tumor permeation in order to improve local tumor control and to lower treatment-related morbidity. Following the validation of this concept for the uterine cervix, proximal vagina and vulva, this study explores its applicability for the distal vagina. METHODS: Serial transverse sections of female embryos and fetuses aged 8-17 weeks were assessed for the morphological changes in the region defined by the deep urogenital sinus-vaginal plate complex. Histopathological pattern analysis of local tumor spread was performed with carcinomas of the lower genital tract involving the distal vagina to test the compartment theory. RESULTS: Ontogenetically, the female urethra, urethrovaginal septum, distal vagina and rectovaginal septum represent a morphogenetic unit derived from the deep urogenital sinus-vaginal plate complex. Herein, the posterior urethra, the urethrovaginal septum and the distal vagina form a distinct subcompartment differentiated from the dorsal wall of the urogenital sinus. From 150 consecutive patients with distal vaginectomy as part of their surgical treatment 26 carcinomas of the lower genital tract had infiltrated the distal vagina. All 22 tumors involving the ventral wall invaded the urethra/periurethral tissue. Of the five carcinomas involving the dorsal wall none invaded the rectum/mesorectum. CONCLUSION: The pattern of local tumor permeation of lower genital tract cancer in the distal vagina can be consistently explained with ontogenetic anatomy and the compartment theory.

Developmental origin of vaginal epithelium.

The developmental origin of vaginal epithelium has been controversial for nearly a century, with speculation that vaginal epithelium originates from the Müllerian duct, Wolffian duct, and/or urogenital sinus. None of these possibilities have been definitively proven or disproven by direct scientific data. To define precisely the origin of vaginal epithelium, epithelial cells of the Müllerian duct, Wolffian duct, or urogenital sinus were fluorescently labeled in mouse embryos by crossing tdTomato-EGFP dual-reporter transgenic mice with transgenic mouse lines that express Cre-recombinase in each type of epithelium. In embryos and newborn mice, the vagina consisted of fused Müllerian ducts plus the sinus vagina of urogenital sinus origin. However, the proportion of the sinus vagina was significantly reduced as the Müllerian vagina grew caudally. By postpartum day 7, the Müllerian vagina extended to the caudal end of the body, whereas the sinus vagina remained only at the junction between the vagina and perineal skin. As the vagina opened in puberty, urogenital sinus epithelium was detected only in the vulva, but not in the vagina. Additionally, from embryo to adult stages, residual Wolffian duct epithelium was present in the dorsolateral stromal wall of the vagina, but not within vaginal or vulvar epithelium. In conclusion, adult mouse vaginal epithelium is derived solely from Müllerian duct epithelium.

Animal Models and Alternatives in Vaginal Research: a Comparative Review.

While developments in gynecologic health research continue advancing, relatively few groups specifically focus on vaginal tissue research for areas like wound healing, device development, and/or drug toxicity. Currently, there is no standardized animal or tissue model that mimics the full complexity of the human vagina. Certain practical factors such as appropriate size and anatomy, costs, and tissue environment vary across species and moreover fail to emulate all aspects of the human vagina. Thus, investigators are tasked with compromising specific properties of the vaginal environment as it relates to human physiology to suit their particular scientific question. Our review aims to facilitate the appropriate selection of a model aptly addressing a particular study by discussing pertinent vaginal characteristics of conventional animal and tissue models. In this review, we first cover common laboratory animals studied in vaginal research-mouse, rat, rabbit, minipig, and sheep-as well as human, with respect to the estrus cycle and related hormones, basic reproductive anatomy, the composition of vaginal layers, developmental epithelial origin, and microflora. In light of these relevant comparative metrics, we discuss potential selection criteria for choosing an appropriate animal vaginal model. Finally, we allude to the exciting prospects of increasing biomimicry for in vitro applications to provide a framework for investigators to model, interpret, and predict human vaginal health.

Local spread of cervical cancer revisited: a clinical and pathological pattern analysis.

BACKGROUND: Local tumor spread of cervical cancer is currently considered as radial progressive intra- and extracervical permeation. For radical tumor resection or radiation the inclusion of a wide envelope of tumor-free tissue is demanded. However, this concept may lead to considerable treatment-related morbidity and does not prevent local relapse. We propose an alternative model of local tumor propagation involving permissive compartments related to embryonic development. METHODS: We analyzed local tumor spread macroscopically and microscopically in consecutive patients with advanced cervical cancer and post-irradiation recurrences. RESULTS: Macroscopically, all 33 stage I B (>2cm) tumors, 40 of 42 stage II tumors and 32 of 44 stage III B tumors were confined to the embryologically defined uterovaginal (Müllerian) compartment. Local tumor permeation deformed the uterovaginal compartment mirroring the mesenchyme distribution of the Müllerian anlage at the corresponding pelvic level in cases of symmetrical tumor growth. Tumor transgression into adjacent compartments mainly involved the embryologically related lower urinary tract. Compartmental transgression was associated with larger tumor size, paradox improvement in oxygenation and an increase in microvessel density. Post-irradiation pelvic relapse landscapes were congruent with the inflated Müllerian compartment. Microscopically, all locally advanced primary cancers and post-irradiation recurrences were confined to the uterovaginal and lower urinary tract compartments. CONCLUSION: Cervical cancer spreads locally within the uterovaginal compartment derived from the Müllerian anlage. Compartment transgression is a relatively late event in the natural disease course associated with distinct phenotypic changes of the tumor. Compartmental tumor permeation suggests a new definition of local treatment radicality.