Single-cell transcriptomic profiling of the neonatal oviduct and uterus reveals new insights into upper Müllerian duct regionalization.

The upper Müllerian duct (MD) is patterned and specified into two morphologically and functionally distinct organs, the oviduct and uterus. It is known that this regionalization process is instructed by inductive signals from the adjacent mesenchyme. However, the interaction landscape between epithelium and mesenchyme during upper MD development remains largely unknown. Here, we performed single-cell transcriptomic profiling of mouse neonatal oviducts and uteri at the initiation of MD epithelial differentiation (postnatal day 3). We identified major cell types including epithelium, mesenchyme, pericytes, mesothelium, endothelium, and immune cells in both organs with established markers. Moreover, we uncovered region-specific epithelial and mesenchymal subpopulations and then deduced region-specific ligand-receptor pairs mediating mesenchymal-epithelial interactions along the craniocaudal axis. Unexpectedly, we discovered a mesenchymal subpopulation marked by neurofilaments with specific localizations at the mesometrial pole of both the neonatal oviduct and uterus. Lastly, we analyzed and revealed organ-specific signature genes of pericytes and mesothelial cells. Taken together, our study enriches our knowledge of upper MD development, and provides a manageable list of potential genes, pathways, and region-specific cell subtypes for future functional studies.

OSR1 disruption contributes to uterine factor infertility via impaired Müllerian duct development and endometrial receptivity.

Three sisters, born from consanguineous parents, manifested a unique Müllerian anomaly characterized by uterine hypoplasia with thin estrogen-unresponsive endometrium and primary amenorrhea, but with spontaneous tubal pregnancies. Through whole-exome sequencing followed by comprehensive genetic analysis, a missense variant was identified in the OSR1 gene. We therefore investigated OSR1/OSR1 expression in postpubertal human uteri, and the prenatal and postnatal expression pattern of Osr1/Osr1 in murine developing Müllerian ducts (MDs) and endometrium, respectively. We then investigated whether Osr1 deletion would affect MD development, using WT and genetically engineered mice. Human uterine OSR1/OSR1 expression was found primarily in the endometrium. Mouse Osr1 was expressed prenatally in MDs and Wolffian ducts (WDs), from rostral to caudal segments, in E13.5 embryos. MDs and WDs were absent on the left side and MDs were rostrally truncated on the right side of E13.5 Osr1-/- embryos. Postnatally, Osr1 was expressed in mouse uteri throughout their lifespan, peaking at postnatal days 14 and 28. Osr1 protein was present primarily in uterine luminal and glandular epithelial cells and in the epithelial cells of mouse oviducts. Through this translational approach, we demonstrated that OSR1 in humans and mice is important for MD development and endometrial receptivity and may be implicated in uterine factor infertility.

Anti-Müllerian Hormone Signal Transduction involved in Müllerian Duct Regression.

Over seventy years ago it was proposed that the fetal testis produces a hormone distinct from testosterone that is required for complete male sexual development. At the time the hormone had not yet been identified but was invoked by Alfred Jost to explain why the Müllerian duct, which develops into the female reproductive tract, regresses in the male fetus. That hormone, anti-Müllerian hormone (AMH), and its specific receptor, AMHR2, have now been extensively characterized and belong to the transforming growth factor-ß families of protein ligands and receptors involved in growth and differentiation. Much is now known about the downstream events set in motion after AMH engages AMHR2 at the surface of specific Müllerian duct cells and initiates a cascade of molecular interactions that ultimately terminate in the nucleus as activated transcription factors. The signals generated by the AMH signaling pathway are then integrated with signals coming from other pathways and culminate in a complex gene regulatory program that redirects cellular functions and fates and leads to Müllerian duct regression.

Single-port thoracoscopic resection of a posterior mediastinal Mullerian cyst in a woman.

Mullerian cysts are benign tumors that are very rare in the posterior mediastinum. It is necessary to distinguish Mullerian cysts from benign tumors or other types of cyst in the posterior mediastinum. A 42-year-old woman visited our hospital for a routine check-up, and a mediastinal mass was identified on chest computed tomography (CT). Contrast-enhanced chest magnetic resonance imaging (MRI) revealed a 4.0 × 2.6 × 2.8-cm mass, and a neurogenic tumor or esophageal cyst was suspected. Single-port thoracoscopic surgery was performed for cyst removal. Histopathological examination of the resected tissue revealed that the cyst wall was covered with a single layer of ciliated columnar epithelium. Immunohistochemical staining revealed positivity for paired box gene 8 (PAX8), Wilms tumor protein 1 (WT-1), estrogen receptor (ER), and progesterone receptor (PR). Therefore, a diagnosis of mediastinal Mullerian cyst was made. Mediastinal Mullerian cysts should be included in the differential diagnosis of posterior mediastinal cysts. Cystic lesions in the posterior mediastinum should be removed surgically and undergo immunohistochemical examination.

Anti-Müllerian hormone: A function beyond the Müllerian structures.

The anti-Müllerian hormone (AMH) is a heterodimeric glycoprotein belonging to the TGFb superfamily implicated in human embryonic development. This hormone was first described as allowing regression of the epithelial embryonic Müllerian structures in males, which would otherwise differentiate into the uterus and fallopian tubes. It activates a signaling pathway mediated by two transmembrane receptors. Binding of AMH to its receptor induces morphological changes leading to the degeneration of Müllerian ducts. Recently, new data has shown the role played by this hormone on structures other than the genital tract. If testicular AMH expression decreases in humans over the course of a lifetime, synthesis may persist in other tissues in adulthood. The mechanisms underlying its production have been unveiled. The aim of this review is to describe the different pathways in which AMH has been identified and plays a pivotal role.

Association of antimullerian hormone with the size of the appendix testis, the androgen and estrogen receptors and their expression in the appendix testis, in congenital cryptorchidism.

OBJECTIVES: Antimullerian hormone (AMH) causes regression of the mullerian ducts in the male fetus. The appendix testis (AT) is a vestigial remnant of mullerian duct origin, containing both androgen (AR) and estrogen (ER) receptors. The role of both AMH and AT in testicular descent is yet to be studied. We investigated the possible association of AMH with AT size, the AR and ER, and their expression in the AT, in congenital cryptorchidism. METHODS: A total of 26 patients with congenital unilateral cryptorchidism and 26 controls with orthotopic testes were investigated, and 21 ATs were identified in each group. AMH and insulin-like three hormone (INSL3) concentrations were measured with spectrophotometry. AR and ER receptor expression was assessed with immunohistochemistry using monoclonal antibodies R441 for AR and MAB463 for ER. For the estimation of receptor expression, the Allred Score method was used. RESULTS: AMH concentrations did not present significant differences between patients with congenital cryptorchidism and the controls. Also, no correlation was found between AMH, INSL3, and AT length. Allred scores did not present significant differences. However, expression percentiles and intensity for both receptors presented significant differences. Three children with cryptorchidism and the highest AMH levels also had the highest estrogen receptor scores in the AT. CONCLUSIONS: No association was found between AMH and the studied major parameters. However, higher AMH concentrations, in combination with higher estrogen receptor scores in the AT, may play a role in cryptorchidism in some children. Larger population samples are needed to verify this observation.

Molecular mechanisms of estrogen action in female genital tract development.

The development of the female reproductive tract can be divided into three parts consisting of Müllerian duct organogenesis, pre-sexual maturation organ development, and post-sexual maturation hormonal regulation. In primates, Müllerian duct organogenesis proceeds in an estrogen independent fashion based on transcriptional pathways that are suppressed in males by the presence of AMH and SRY. However, clinical experience indicates that exposure to xenoestrogens such as diethylstilbestrol (DES) during critical periods including late organogenesis and pre-sexual maturational development can have substantial effects on uterine morphology, and confer increased risk of disease states later in life. Recent evidence has demonstrated that these effects are in part due to epigenetic regulation of gene expression, both in the form of aberrant CpG methylation, and accompanying histone modifications. While xenoestrogens and selective estrogen receptor modulators (SERMS) both can induce non-canonical binding confirmations in estrogen receptors, the primate specific fetal estrogens Estriol and Estetrol may act in a similar fashion to alter gene expression through tissue specific epigenetic modulation.

Comprehensive immunohistochemical analysis of the gastrointestinal and Müllerian phenotypes of 139 ovarian mucinous cystadenomas.

Mucinous cystadenoma is one of the most common benign ovarian neoplasms. The immunophenotypes and histogenetic relationships of mucinous cystadenomas with a Müllerian-type epithelium have not been fully explored. We elucidated the direction of differentiation of the mucinous epithelium that constitutes mucinous cystadenomas. Special attention was paid to the existence of gastrointestinal (GI)-type mucinous epithelium, and its association with background Müllerian-type epithelium. Immunohistochemistry was performed in 139 cases of mucinous cystadenoma to evaluate the expression of Claudin-18 (CLDN18), a novel marker of gastric differentiation; CDX2, a marker of intestinal differentiation; and estrogen receptor (ER), a marker of Müllerian differentiation. We found that GI differentiation characterized by CLDN18 and/or CDX2 positivity was observed in mucinous epithelium of most mucinous cystadenomas (129/139 cases, 93%). In a subset of these cases, the tumor was composed of mucinous epithelium exhibiting an intermediate GI and Müllerian phenotype (CLDN18+/CDX2±/ER+). Of note, in 12 cases, a transition from background Müllerian-type epithelium to mucinous epithelium with GI differentiation was identified. A minor subset (6%) of mucinous cystadenomas was considered a pure Müllerian type because the epithelium exhibited a CLDN18-/CDX2-/ER + immunophenotype. In conclusion, mucinous cystadenomas consist of three major subtypes: GI, Müllerian, and intermediate types. Most mucinous cystadenomas are GI-type, and they should be considered a precursor of GI-type mucinous borderline tumors. The existence of intermediate-type mucinous cystadenomas, and areas of transition from Müllerian-type to GI-type epithelium suggest that GI-type mucinous epithelium can arise from Müllerian duct derivatives or surface epithelium exhibiting Müllerian metaplasia in the ovary.

New frontiers of developmental endocrinology opened by researchers connecting irreversible effects of sex hormones on developing organs.

In the early 1960's, at Professor Bern's laboratory, University of California, Berkeley) in the US, Takasugi discovered ovary-independent, persistent vaginal changes in mice exposed neonatally to estrogen, which resulted in vaginal cancer later in life. Reproductive abnormalities in rodents were reported as a result of perinatal exposure to various estrogenic chemicals. Ten years later, vaginal cancers were reported in young women exposed in utero to the synthetic estrogen diethylstilbestrol (DES) and this has been called the "DES syndrome". The developing organism is particularly sensitive to developmental exposure to estrogens inducing long-term changes in various organs including the reproductive organs. The molecular mechanism underlying the persistent vaginal changes induced by perinatal estrogen exposure was partly demonstrated. Persistent phosphorylation and sustained expression of EGF-like growth factors, lead to estrogen receptor α (ESR1) activation, and then persistent vaginal epithelial cell proliferation. Agents which are weakly estrogenic by postnatal criteria may have major developmental effects, especially during a critical perinatal period. The present review outlines various studies conducted by four generations of investigators all under the influence of Prof. Bern. The studies include reports of persistent changes induced by neonatal androgen exposure, analyses of estrogen responsive genes, factors determining epithelial differentiation in the Müllerian duct, ESR and growth factor signaling, and polyovular follicles in mammals. This review is then expanded to the studies on the effects of environmental estrogens on wildlife and endocrine disruption in Daphnids.

Anthropometric biomarkers for abnormal prenatal reproductive hormone exposure in women with Mayer-Rokitanksy-Küster-Hauser syndrome, polycystic ovary syndrome, and endometriosis.

OBJECTIVE: To study whether markers of prenatal exposure to reproductive hormones are related to Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome, polycystic ovary syndrome (PCOS), and endometriosis. DESIGN: Case-control study. Comparison of sex hormone-related external genital and digital characteristics in cases and controls. SETTING: University hospital. PATIENT(S): We enrolled 172 women in four groups-women with MKRH, women with PCOS, women with endometriosis, and controls (43 in each group). INTERVENTION(S): Measurement of two anthropometric biomarkers: anogenital distance and digit ratio. MAIN OUTCOME MEASURE(S): Anogenital distance was measured from the anus to the anterior clitoral surface (AGDac) and from the anus to the posterior fourchette (AGDaf). For the digit ratio we used a direct, as well as a computer-assisted graphic measurement to measure the length of the second and fourth digit. RESULT(S): After adjustment for body mass index and age, AGDac was the shortest in endometriosis and the longest in PCOS groups, with a mean difference of 10 mm (95% confidence interval 3.1-16.8). AGDaf but not AGDac measures were found to be significantly larger in the MRKH group, with a mean difference compared with controls of 2.6 mm (95% confidence interval 0.1-5.2). The digit ratio was not significantly different between the groups. CONCLUSION(S): In this study we did find limited evidence for androgen exposure during the development of MRKH. This is compatible with the hypothesis that the uterovaginal agenesis may have been the result of temporary prenatal exposure to altered gonadal hormone concentrations. For endometriosis and PCOS we confirm previously observed associations for anogenital distance reflecting possible estrogen-based and androgen-based intrauterine origins, respectively. DUTCH TRIAL REGISTRATION NUMBER: NTR7492.

Lats1 and Lats2 are required for the maintenance of multipotency in the Müllerian duct mesenchyme.

WNT signaling plays essential roles in the development and function of the female reproductive tract. Although crosstalk with the Hippo pathway is a key regulator of WNT signaling, whether Hippo itself plays a role in female reproductive biology remains largely unknown. Here, we show that conditional deletion of the key Hippo kinases Lats1 and Lats2 in mouse Müllerian duct mesenchyme cells caused them to adopt the myofibroblast cell fate, resulting in profound reproductive tract developmental defects and sterility. Myofibroblast differentiation was attributed to increased YAP and TAZ expression (but not to altered WNT signaling), leading to the direct transcriptional upregulation of Ctgf and the activation of the myofibroblast genetic program. Müllerian duct mesenchyme cells also became myofibroblasts in male mutant embryos, which impeded the development of the male reproductive tract and resulted in cryptorchidism. The inactivation of Lats1/2 in differentiated uterine stromal cells in vitro did not compromise their ability to decidualize, suggesting that Hippo is dispensable during implantation. We conclude that Hippo signaling is required to suppress the myofibroblast genetic program and maintain multipotency in Müllerian mesenchyme cells.

Targeted ablation of Wnt4 and Wnt5a in Müllerian duct mesenchyme impedes endometrial gland development and causes partial Müllerian agenesis.

Wnt4 and Wnt5a have well-established roles in the embryonic development of the female reproductive tract, as well as in implantation, decidualization, and ovarian function in adult mice. Although these roles appear to overlap, whether Wnt5a and Wnt4 are functionally redundant in these tissues has not been determined. We addressed this by concomitantly inactivating Wnt4 and Wnt5a in the Müllerian mesenchyme and in ovarian granulosa cells by crossing mice bearing floxed alleles to the Amhr2cre strain. Whereas fertility was reduced by ∼50% in Wnt4flox/flox; Amhr2cre/+ and Wnt5aflox/flox; Amhr2cre/+ females, Wnt4flox/flox; Wnt5aflox/flox; Amhr2cre/+ mice were either nearly or completely sterile. Loss of fertility was not due to an ovarian defect, as serum ovarian hormone levels, follicle counts, and ovulation rates were comparable to controls. Conversely, the uterus was abnormal in Wnt4flox/flox; Wnt5aflox/flox; Amhr2cre/+ mice, with thin myometrial and stromal layers, frequent fibrosis and a >90% reduction in numbers of uterine glands, suggesting redundant or additive roles of Wnt4 and Wnt5a in uterine adenogenesis. Loss of fertility in Wnt4flox/flox; Wnt5aflox/flox; Amhr2cre/+ mice was attributed to defects in decidualization, implantation, and placental development, the severity of which were proportional to the extent of gland loss. Furthermore, a third of Wnt4flox/flox; Wnt5aflox/flox; Amhr2cre/+ females had a partial agenesis of Müllerian duct-derived structures, but with normal oviducts and ovaries. Together, our results suggest that Wnt4 and Wnt5a play redundant roles in the development of the female reproductive tract, and may provide insight into the etiology of certain cases of Müllerian agenesis in women.

A Comparison of GATA3, TTF1, CD10, and Calretinin in Identifying Mesonephric and Mesonephric-like Carcinomas of the Gynecologic Tract.

Mesonephric carcinomas of the gynecologic tract are neoplasms that are often under-recognized due to their varied morphologic appearances. Recently, GATA3 and TTF1 have been reported to be useful immunohistochemical markers for distinguishing mesonephric carcinomas from its morphologic mimics. Herein, we compared the performance of GATA3 and TTF1 to the traditional markers used for mesonephric carcinomas, CD10 and calretinin. We studied 694 cases: 8 mesonephric carcinomas (7 cervical [includes 3 mesonephric carcinosarcomas], 1 vaginal), 5 mesonephric-like carcinomas (4 uterine corpus, 1 ovarian), 585 endometrial adenocarcinomas, and 96 cervical adenocarcinomas. Mesonephric-like carcinomas were defined as tumors exhibiting the classic morphologic features of mesonephric carcinoma, but occurring outside of the cervix and without convincing mesonephric remnants. GATA3 had the highest sensitivity and specificity (91% and 94%) compared with TTF1 (45% and 99%), CD10 (73% and 83%), and calretinin (36% and 89%). GATA3, however, also stained a substantial number of uterine carcinosarcomas (23/113, 20%). TTF1 was positive in 5/5 (100%) mesonephric-like carcinomas and only 1/8 (13%) mesonephric carcinomas. In 4/6 (67%) TTF1 positive cases, GATA3 exhibited an inverse staining pattern with TTF1. In summary, GATA3 was the best overall marker for mesonephric and mesonephric-like carcinomas, but cannot be used to distinguish mesonephric carcinosarcomas from Müllerian carcinosarcomas. The inverse staining pattern between GATA3 and TTF1, suggests that TTF1 may be useful when GATA3 is negative in small biopsies where mesonephric or mesonephric-like carcinoma is suspected. The greater TTF1 positivity in mesonephric-like carcinomas suggests they may be biologically different from prototypical mesonephric carcinomas.

Pathogenesis of uterine adenomyosis: invagination or metaplasia?

Adenomyosis is a commonly diagnosed estrogen-dependent gynecological disorder that causes pelvic pain, abnormal uterine bleeding, and infertility. Despite its prevalence and severity of symptoms, its pathogenesis and etiology have not yet been elucidated. The aim of this manuscript is to review the different hypotheses on the origin of adenomyotic lesions and the mechanisms involved in the evolution and progression of the disease. Two main theories have been proposed to explain the origin of adenomyosis. The most common suggests involvement of tissue injury and the repair mechanism and claims that adenomyosis results from invagination of the endometrial basalis into the myometrium. An alternative theory maintains that adenomyotic lesions result from metaplasia of displaced embryonic pluripotent Müllerian remnants or differentiation of adult stem cells. Previous investigations performed in human adenomyotic lesions and corroborated by studies in mice supported the involvement of the epithelial-mesenchymal transition process in the early stages of progression and spread of adenomyosis. However, studies conducted in a recently developed baboon model indicate that collective cell migration may be implicated in the later events of invasion. This suggests that the invasiveness of this complex uterine disorder is not driven by a single mechanism of migration but by a time-dependent combination of two processes.

Molecular mechanisms of development of the human fetal female reproductive tract.

Human female reproductive tract development rests mostly upon hematoxilyn and eosin stained sections despite recent advances on molecular mechanisms in mouse studies. We report application of immunohistochemical methods to explore the ontogeny of epithelial and mesenchymal differentiation markers (keratins, homobox proteins, steroid receptors), transcription factors and signaling molecules (TP63 and RUNX1) during human female reproductive tract development. Keratins 6, 7, 8, 10, 14 and 19 (KRT6, KRT7, KRT8, KRT10, KRT14, KRT19) were expressed in a temporally and spatially dynamic fashion. The undifferentiated Müllerian duct and uterovaginal canal, lined by simple columnar epithelia, expressed KRT7, KRT8 and KRT19. Glandular derivatives of the Müllerian duct (uterine tube, uterine corpus and endocervix) maintained expression of these keratins, while tissues that undergo stratified squamous differentiation (exocervix and vagina) expressed KRT6, KRT14 and KRT10 during development in an age-dependent fashion. TP63 and RUNX1 were expressed prior to KRT14, as these two transcription factors are known to be upstream from KRT14 in developing Müllerian epithelium. In the vagina, KRT10, a marker of terminal differentiation, appeared after endogenous estrogens transformed the epithelium to a thick glycogenated squamous epithelium. Uroplakin, a protein unique to urothelium, was expressed only in the bladder, urethra and vaginal introitus, but not in the female reproductive tract itself. Mesenchymal differentiation was examined through immunostaining for HOXA11 (expressed in uterine mesenchyme) and ISL1 (expressed in vaginal mesenchyme). A detailed ontogeny of estrogen receptor alpha (ESR1), progesterone receptor (PGR) and the androgen receptor (AR) provides the mechanistic underpinning for the teratogenicity of estrogens, progestins and androgens on female reproductive tract development. Immunohistochemical analysis of differentiation markers and signaling molecules advance our understanding of normal development of the human female reproductive tract. These observations demonstrate remarkable similarities in mouse and human female reproductive tract development, but also highlight some key differences.

The possible role of AMH in shortening the gubernacular cord in testicular descent: A reappraisal of the evidence.

BACKGROUND/AIM: Anti-Müllerian hormone (AMH), also called Müllerian inhibiting substance (MIS), is glycoprotein hormone secreted by the fetal Sertoli cells to regulate regression of the Müllerian ducts, the anlagen of the uterus, fallopian tubes, and upper vagina. After its existence was predicted in 1946 and its isolation and purification in the 1970's, a huge amount of information has been gathered on its molecular biology and function in the last 30-40years. Once thought to be a locally acting factor in the male fetus during sexual differentiation, it is now recognized as an endocrine hormone present in both sexes and with functions throughout life. One of the remaining controversies is the possible role of AMH during fetal testicular descent. In the human with aberrant AMH function, the boy has cryptorchidism with persistent Müllerian duct syndrome (PMDS), where the testes are often intraabdominal and on an abnormally long gubernacular cord. By contrast, in rodent models knockout of the AMH gene does not cause cryptorchidism. METHODS/RESULTS: In this review we examined the evidence in the literature for and against a role for AMH in testicular descent and considered the implications of the different anatomy of the gubernacular cord in rodents versus children. CONCLUSION: We conclude that AMH may have a role in shortening the gubernacular cord in humans which is concealed in rodent models by differences in anatomy of the gubernacular cord in rodents. The controversy could be resolved by re-examination of the gubernacular cord in boys with PMDS and mice with AMHKO. TYPE OF STUDY: Review. LEVEL OF EVIDENCE: V.

Decidualization is Impaired in Endometrial Stromal Cells from Uterine Rudiments in Mayer-Rokitansky-Küster-Hauser Syndrome.

BACKGROUND/AIMS: Uterine rudiments from patients with Mayer-Rokitansky-Küster-Hauser syndrome (MRKHS) contain all tissues typically found in the uterus. Endometrium from the rudiments predominantly exhibits basalis-like features, and endometrial proliferative capacity in patients' epithelium and stroma is significantly lower. METHODS: This single-center, prospective study conducted at a major German university hospital compared in-vitro decidualization in cultured ESCs from MRKHS patients and hysterectomy controls. Primary ESC cultures were established from both sources. Hormone-induced prolactin and IGFBP-1 secretion served as a measure of their ability to undergo decidualization in response to hormonal stimulation. Expression levels of 8 key marker genes of decidualization were also determined. RESULTS: At day 9, mean secretion of prolactin and IGFBP-1 was significantly reduced by 89.0% and 99.5%, respectively, in MRKHS ESCs vs. hysterectomy controls, both indicating impaired decidualization of MRKHS ESCs. Key decidual markers confirmed impaired decidualization in MRKHS patients. CONCLUSION: Our results indicate that the ESCs from MRKHS patients lack hormone responsiveness as a potential sign of dysfunctional hormone receptor function, which may also play a role in the onset of MRKHS. Further studies are needed to corroborate our findings, directly address receptor function, and elucidate the role of other potential determinants of uterine development and adult function.

Specific deletion of LKB1/Stk11 in the Müllerian duct mesenchyme drives hyperplasia of the periurethral stroma and tumorigenesis in male mice.

Nearly all older men will experience lower urinary tract symptoms associated with benign prostatic hyperplasia (BPH), the etiology of which is not well understood. We have generated Stk11CKO mice by conditional deletion of the liver kinase B1 (LKB1) tumor suppressor gene, Stk11 (serine threonine kinase 11), in the fetal Müllerian duct mesenchyme (MDM), the caudal remnant of which is thought to be assimilated by the urogenital sinus primordial mesenchyme in males during fetal development. We show that MDM cells contribute to the postnatal stromal cells at the dorsal aspect of the prostatic urethra by lineage tracing. The Stk11CKO mice develop prostatic hyperplasia with bladder outlet obstruction, most likely because of stromal expansion. The stromal areas from prostates of Stk11CKO mice, with or without significant expansion, were estrogen receptor positive, which is consistent with both MD mesenchyme-derived cells and the purported importance of estrogen receptors in BPH development and/or progression. In some cases, stromal hyperplasia was admixed with epithelial metaplasia, sometimes with keratin pearls, consistent with squamous cell carcinomas. Mice with conditional deletion of both Stk11 and Pten developed similar features as the Stk11CKO mice, but at a highly accelerated rate, often within the first few months after birth. Western blot analyses showed that the loss of LKB1 and phosphatase and tensin homolog deleted on chromosome 10 (PTEN) induces activation of the phospho-5' adenosine monophosphate-activated protein kinase and phospho-AKT serine/threonine kinase 1 signaling pathways, as well as increased total and active ß-catenin. These results suggest that activation of these signaling pathways can induce hyperplasia of the MD stroma, which could play a significant role in the etiology of human BPH.

Efficacy of Fibroblast Growth Factor on Epithelialization of the Neovagina in Patients with Mayer-Rokitansky-Küster-Hauser Syndrome Who Underwent Vaginoplasty.

STUDY OBJECTIVE: To evaluate the effect of fibroblast growth factor (FGF) on epithelialization of neovagina in patients with Mayer-Rokitansky-Küster-Hauser syndrome who underwent vaginoplasty. DESIGN: Observational study. SETTING: University hospital. PARTICIPANTS: Seven patients with Mayer-Rokitansky-Küster-Hauser syndrome. INTERVENTIONS: Cytological examination was done on vaginal smear samples from the site of completed epithelialization, and tissue was collected from the epithelialized part for histological evaluation. Immunostaining for estrogen receptor α, and keratin 13 and 14, and reverse transcription polymerase chain reaction (RT-PCR) analysis of the FGF receptor (FGFR) 1-4 were performed in samples from case 2 three times (ie, during the surgery, during the period of vaginal creation, and at 3 months and 6 months after the surgery). MAIN OUTCOME MEASURES: The primary outcome was the FGF effects on the epithelialization speed and FGFR expression in the neovagina. The second was the role of FGF in the mechanism of vaginal epithelial cell proliferation. RESULTS: The histological structure of the neovagina was consistent with that of normal vagina. RT-PCR analysis revealed that FGFR was expressed in the control vaginas and neovaginas. Among the FGFR subtypes, FGFR-4 was overexpressed during the process of epithelialization and its level decreased after completion of creation of the new vagina. CONCLUSION: The epithelium of the neovagina was morphologically similar to that of normal vagina. It is suggested that FGF plays the role as a growth factor.

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.