Comparison of the effect of oestradiol, tamoxifen and raloxifene on nerve growth factor-alpha expression in specific neonatal mouse uterine cell types using laser capture microdissection

Cracking the enigma of adenomyosis: an update on its pathogenesis and pathophysiology

In brief

Traditionally viewed as enigmatic and elusive, adenomyosis is a fairly common gynecological disease but is under-recognized and under-researched. This review summarizes the latest development on the pathogenesis and pathophysiology of adenomyosis, which have important implications for imaging diagnosis of the disease and for the development of non-hormonal therapeutics.

Abstract

Traditionally considered as an enigmatic disease, adenomyosis is a uterine disease that affects many women of reproductive age and is a contributing factor for pelvic pain, heavy menstrual bleeding (HMB), and subfertility. In this review, the new development in the pathogenesis and pathophysiology of adenomyosis has been summarized, along with their clinical implications. After reviewing the progress in our understanding of the pathogenesis and describing the prevailing theories, in conjunction with their deficiencies, a new hypothesis, called endometrial-myometrial interface disruption (EMID), which is backed by extensive epidemiologic data and demonstrated by a mouse model, is reviewed, along with recent data implicating the role of Schwann cells in the EMI area in the genesis of adenomyosis. Additionally, the natural history of adenomyotic lesions is elaborated and underscores that, in essence, adenomyotic lesions are fundamentally wounds undergoing repeated tissue injury and repair (ReTIAR), which progress to fibrosis through epithelial-mesenchymal transition, fibroblast-to-myofibroblast transdifferentiation, and smooth muscle metaplasia. Increasing lesional fibrosis propagates into the neighboring EMI and endometrium. The increased endometrial fibrosis, with ensuing greater tissue stiffness, results in attenuated prostaglandin E2, hypoxia signaling and glycolysis, impairing endometrial repair and causing HMB. Compared with adenomyosis-associated HMB, the mechanisms underlying adenomyosis-associated pain are less understood but presumably involve increased uterine contractility, hyperinnervation, increased lesional production of pain mediators, and central sensitization. Viewed through the prism of ReTIAR, a new imaging technique can be used to diagnose adenomyosis more accurately and informatively and possibly help to choose the best treatment modality.

Analysis of the Mechanism of GuizhiFuling Wan in Treating Adenomyosis Based on Network Pharmacology Combined with Molecular Docking and Experimental Verification

Background

The effect of GuizhiFuling Wan (GFW) on adenomyosis (AM) is definite. This study aimed to explore the mechanism and key therapeutic targets of GFW in treating AM through network pharmacology combined with molecular docking and experimental verification.

Materials and Methods

In network pharmacology, firstly, the active components of GFW, its drug, and disease targets were screened through several related public databases, and GFW-AM common targets were obtained after the intersection. Then, the biological function (Gene Ontology, GO) and pathway (Kyoto Encyclopedia of Genes and Genomes, KEGG) of GFW in treating AM were enriched and analyzed. Finally, the interaction and binding force between key components and key targets of GFW were verified by molecular docking. In the animal part, the effect of GFW on the expression of matrix metallopeptidase 2 (MMP-2), matrix metallopeptidase 9 (MMP-9), and vascular endothelial growth factor (VEGF) in mice with AM was observed by HE staining, ELISA, and immunohistochemistry.

Results

In this study, 89 active components of GFW, 102 related targets, and 291 targets of AM were collected. After the intersection, 26 common targets were finally obtained. The key active compounds were baicalein, sitosterol, and β-sitosterol, and the key targets were MMP-2, MMP-9, and VEGF. GO and KEGG enrichment analyses showed that biological processes such as the positive regulation of vascular endothelial migration and signaling pathways such as TNF and HIF-1 were involved in regulating angiogenesis, invasion, and metastasis in AM. The molecular docking results showed that baicalein, β-sitosterol, and stigmasterol had better binding potential with MMP-2, MMP-9, and VEGF. The results of in vivo analysis showed that GFW could decrease the serum content and protein expression of MMP-2, MMP-9, and VEGF in mice with AM.

Conclusions

GFW could reduce the expression of MMP-2, MMP-9, and VEGF, which might be an essential mechanism for GFW to inhibit the invasion and metastasis of ectopic tissues of AM.

Perioperative Suppression of Schwann Cell Dedifferentiation Reduces the Risk of Adenomyosis Resulting from Endometrial–Myometrial Interface Disruption in Mice

We have recently demonstrated that endometrial–myometrial interface (EMI) disruption (EMID) can cause adenomyosis in mice, providing experimental evidence for the well-documented epidemiological finding that iatrogenic uterine procedures increase the risk of adenomyosis. To further elucidate its underlying mechanisms, we designed this study to test the hypothesis that Schwann cells (SCs) dedifferentiating after EMID facilitate the genesis of adenomyosis, but the suppression of SC dedifferentiation perioperatively reduces the risk. We treated mice perioperatively with either mitogen-activated protein kinase kinase (MEK)/extracellular-signal regulated protein kinase (ERK) or c-Jun N-terminal kinase (JNK) inhibitors or a vehicle 4 h before and 24 h, 48 h and 72 h after the EMID procedure. We found that EMID resulted in progressive SCs dedifferentiation, concomitant with an increased abundance of epithelial cells in the myometrium and a subsequent epithelial–mesenchymal transition (EMT). This EMID-induced change was abrogated significantly with perioperative administration of JNK or MEK/ERK inhibitors. Consistently, perioperative administration of a JNK or a MEK/ERK inhibitor reduced the incidence by nearly 33.5% and 14.3%, respectively, in conjunction with reduced myometrial infiltration of adenomyosis and alleviation of adenomyosis-associated hyperalgesia. Both treatments significantly decelerated the establishment of adenomyosis and progression of EMT, fibroblast-to-myofibroblast trans-differentiation and fibrogenesis in adenomyotic lesions. Thus, we provide the first piece of evidence strongly implicating the involvement of SCs in the pathogenesis of adenomyosis induced by EMID.

Animal Models of Adenomyosis

Adenomyosis is a nonmalignant uterine disorder in which endometrial tissue exists within and grows into the myometrium. Animal models have generated limited insight into the still-unclear pathogenesis of adenomyosis, provided a platform for preclinical screening of many drugs and compounds with potential as therapeutics, and elucidated mechanisms underlying the pain and fertility issues that occur in many women with the disease. Spontaneous adenomyosis has been studied in nonhuman primates, primarily in the form of case reports. Adenomyosis is routinely experimentally induced in mice through methods such as neonatal tamoxifen exposure, pituitary engraftment, and human tissue xenotransplantation. Several studies have also reported hormonal or environmental toxicant exposures that give rise to murine adenomyosis, and genetically engineered models have been created that recapitulate the human-like condition, most notably involving alteration of β-catenin expression. This review describes the animal models for adenomyosis and their contributions to our understanding of the factors underpinning the development of symptoms. Animal models represent a unique opportunity for understanding the molecular basis of adenomyosis and developing efficacious treatment options for affected women. Herein, we assess their different potentials and limitations with regard to identification of new therapeutic interventions and reflect on future directions for research and drug validation.

GnRH agonist improves pregnancy outcome in mice with induced adenomyosis by restoring endometrial receptivity

Purpose

Adenomyosis has a negative impact on female fertility. GnRH agonist treatment can improve pregnancy outcomes in women with adenomyosis. However, the impact of GnRH agonist upon endometrium receptivity of patients with adenomyosis remains unclear. In this study, endometrial receptivity and pregnancy outcome were investigated using a mouse model of adenomyosis.

Materials and methods

Adenomyosis was induced in 12 female ICR mice, neonatally treated with tamoxifen, while another six female mice (control group) received solvent only. At 75 days, the induced adenomyosis group was randomly divided into two groups: an untreated group and a group treated with GnRH agonist (n = 6 each). Sixty days later, the mice were mated and pregnancy outcomes were observed and compared among the three groups (n = 6 each). In a parallel experiment using the same treatment regimes, uterus samples were collected on day 4 of pregnancy for immunohistochemistry, gene (quantitative polymerase chain reaction) and protein expression (Western blot), and scanning electron microscopy analyses.

Results

We found that the average live litter size was reduced in the adenomyosis compared with control group (8 ± 0.56 versus 13 ± 0.71; P = 0.03). However, the litter size was significantly increased in the treated with GnRH agonist group compared with the untreated group (12 ± 0.35 versus 8 ± 0.56; P = 0.04). The uterine expression levels of Hoxa10, Hoxa11, Lif and integrin b3 mRNA and protein were decreased in the adenomyosis group, and were significantly increased after GnRH agonist treatment. Additionally, pinopodes were reduced in number and poorly developed in mice with induced adenomyosis. However, pinopodes were abundant and well-developed in the GnRH agonist treatment group.

Conclusion

Adenomyosis may have an adverse impact on endometrial receptivity and reduce pregnancy outcomes in mice. However, GnRH agonist may improve the pregnancy outcome by partially restoring endometrial receptivity.

Transcriptome analysis of endometrial tissues following GnRH agonist treatment in a mouse adenomyosis model

Purpose

Adenomyosis is a common, benign gynecological condition of the female reproductive tract characterized by heavy menstrual bleeding and dysmenorrhea. Gonadotropin-releasing hormone (GnRH) agonists are one of the medications used in adenomyosis treatment; however, their underlying mechanisms are poorly understood. Moreover, it is difficult to obtain endometrial samples from women undergoing such treatment. To overcome this, we generated an adenomyosis mouse model, which we treated with an GnRH agonist to determine its effect on pregnancy outcomes. We also analyzed endometrial gene expression following GnRH agonist treatment to determine the mechanisms that may affect pregnancy outcome in individuals with adenomyosis.

Methods

Neonatal female mice were divided into a control group, an untreated adenomyosis group, and an adenomyosis group treated with a GnRH agonist (n=6 each). The pregnancy outcome was observed and compared among the groups. Then, three randomly chosen transcriptomes from endometrial tissues from day 4 of pregnancy were analyzed between the adenomyosis group and the GnRH agonist treatment group by RNA sequencing and quantitative reverse transcription polymerase chain reaction (PCR).

Results

The litter size was significantly smaller in the adenomyosis group than in the control group (7±0.28 vs 11±0.26; P<0.05). However, the average live litter size was increased (10±0.28 vs 7±0.28; P<0.05) after GnRH agonist treatment. Three hundred and fifty-nine genes were differentially expressed in the GnRH agonist-treated group compared with the untreated group (218 were downregulated and 141 were upregulated). Differentially expressed genes were related to diverse biological processes, including estrogen metabolism, cell cycle, and metabolite biosynthesis.

Conclusion

GnRH agonist treatment appears to improve the pregnancy outcome of adenomyosis in a mouse model. Besides pituitary down-regulation, other possible mechanisms such as the regulation of cell proliferation may play a role in this. These new insights into GnRH agonist mechanisms will be useful for future adenomyosis treatment.

Stellate-ganglion block as a treatment for severe postmenopausal flushing

OBJECTIVE

Hormone replacement therapy is the most effective treatment for postmenopausal flushing. Unfortunately, its use is often contraindicated. A limited amount of uncontrolled data suggests that stellate-ganglion block (SGB) may be useful for the treatment of hot flushes. In the present study, we examined whether previously reported results could be reproduced in women with severe postmenopausal flushing.

METHODS

Twenty postmenopausal women with a baseline hot flush score ≥ 15  were treated with SGB in an open, uncontrolled setting. This mean daily hot flush score was calculated as the product of flush frequency and flush severity over a period of 1 week. The response to treatment was evaluated by flush scores and assessment of quality of life at baseline and 4 weeks after SGB.

RESULTS

The per-protocol analysis included 19 women. One woman was excluded because of lack of Horner syndrome after SGB. Four weeks after SGB, the mean flush score had decreased by 34 ± 7.4% (95% confidence interval (CI) 18-49%; p < 0.005). Nine women had a decrease in flush score between 40 and 90%, with a mean response of 65 ± 4.9% (95% CI 53-76%). The other ten women were non-responders with a decrease in flush score between 0 and 11%. Quality of life and sleep, both assessed by questionnaire, improved significantly.

CONCLUSIONS

The results of this study support the observation that SGB may be a useful therapy for a subset of women with severe postmenopausal flushing. A sham-controlled, single-blinded study is warranted to improve the evidence of efficacy.

The pathophysiology of uterine adenomyosis: an update

The diagnosis of adenomyosis using noninvasive techniques such as vaginal ultrasounds and magnetic resonance has clear clinical applications and has renewed the interest in the pathogenesis of uterine adenomyosis. However, the research remains hampered by the lack of consensus on the classification of lesions. Magnetic resonance imaging and transvaginal ultrasound have comparable diagnostic accuracy. Minimal interventional biopsy techniques have recently been introduced. This article reviews human and animal studies and provides an update on the pathophysiology of adenomyosis. Recent views on the pathogenesis and links with endometriosis are discussed.

Accumulation of nerve growth factor and its receptors in the uterus and dorsal root ganglia in a mouse model of adenomyosis

BACKGROUND

Adenomyosis is a common gynecological disease, which is accompanied by a series of immunological and neuroendocrinological changes. Nerve growth factor (NGF) plays a critical role in producing pain, neural plasticity, immunocyte aggregation and release of inflammatory factors. This study aimed to investigate the expression of NGF and its two receptors in uteri and dorsal root ganglia (DRG) in an adenomyosis mouse model, as well as their relationship with the severity of adenomyosis.

METHODS

Forty newborn ICR mice were randomly divided into the adenomyosis model group and control group (n = 20 in each group). Mice in the adenomyosis model group were orally dosed with 2.7 μmol/kg tamoxifen on days 2-5 after birth. Experiments were conducted to identify the expression of NGF- beta and its receptors, tyrosine kinase receptor (trkA) and p75 neurotrophin receptor (p75NTR), in the uterus and DRG in four age groups (90+/-5 d, 140+/-5 d, 190+/-5 d and 240+/-5 d; n = 5 mice in each group) by western bolt, immunochemistry and real time reverse transcription-polymerase chain reaction.

RESULTS

Adenomyosis, which became more serious as age increased, was successfully induced in dosed ICR mice. NGF-beta, trkA and p75NTR protein levels in the uterus and trkA mRNA levels in DRG were higher in the older aged adenomyosis model group than those in controls (190+/-5 d and 240+/-5 d groups, P < 0.05). The expression of NGF-beta and its receptors in the uterus increased gradually as age increased for adenomyosis mice (190+/-5 d and 240+/-5 d, P < 0.05, compared with 90+/-5 d) but it showed little change in control mice. The mRNA level of trkA in DRG also increased as age increased in the adenomyosis model group (190+/-5 d and 240+/-5 d, P < 0.05, compared with 90+/-5 d) but was unchanged in controls. The mRNA level of p75NTR in DRG was not different between the adenomyosis and control groups and was stable from young to old mice.

CONCLUSIONS

NGF- beta can be used as an indicator for the severity of adenomyosis. The gradually increasing level of NGF- beta and its receptors while the disease becomes more severe suggests an effect of NGF- beta on pathogenic mechanisms of adenomyosis.

Signalling molecules involved in mouse bladder smooth muscle cellular differentiation

Mouse bladder mesenchyme differentiates into smooth muscle under the influence of urothelium at gestational day 13.5 (E13.5). Sonic hedgehog (Shh) is considered to be the upstream gene arising from the urothelium, which induces smooth muscle in the peripheral bladder mesenchyme. We hypothesize differential gene expression across the full thickness of bladder mesenchyme as a function of proximity to the inducing bladder urothelium and the peripheral location of the smooth muscle. Embryonic bladders from FVB mice were collected at E12.5, 13.5, 15 and 16 and cryosectioned followed by microdissection with a PixCell II laser capture microscope. RNA extraction was performed at the laser captured sites and mRNA expression profiles were measured using SYBR Green quantitative RT-PCR. Smooth muscle a-actin (SMAA) and smooth muscle myosin heavy chain (SM-MHC) were expressed in the E13.5, E15 and E16 bladders in the peripheral layer of mesenchyme, but not in the prospective submucosa. Patched 1 (Ptc1), Gli1 and bone morphogenetic protein (Bmp) 4 expression was consistently elevated in the mesenchymal layer immediately adjacent to the urothelium compared to the peripheral location at E12.5. After E12.5, Ptc1 expression decreased to an undetectable level throughout the bladder mesenchyme. The level of TGF-beta1 was highest in the mesenchymal layer adjacent to the serosa at E13.5. The level of expression of serum response factor (SRF) was also highest at E15 in the peripheral mesenchyme. Genes downstream of Shh are differentially expressed in the prospective submucosa vs. the peripheral bladder mesenchyme as a function gestation age and smooth muscle differentiation.

Gene expression profiling studies of three SERMs and their conjugated estrogen combinations in human breast cancer cells: insights into the unique antagonistic effects of bazedoxifene on conjugated estrogens

Bazedoxifene (BZA), a new selective estrogen receptor modulator (SERM) was recently approved in Europe for the prevention and treatment of postmenopausal osteoporosis. Combination therapy using BZA and conjugated estrogens (CE) is currently in late stage development representing a new paradigm for the treatment of menopausal symptoms and prevention of osteoporosis. A GeneChip microarray study was designed to compare gene expression profiles of BZA to that of other SERMs, raloxifene (RAL) and lasofoxifene (LAS). In addition, we compared the gene expression profiles of the three SERMs in combination with CE, a mixture of 10 most abundant estrogens present in Premarin. According to the hierarchical clustering heat map analysis, gene clusters that specifically responded to CE treatments or SERM treatments were identified and gene lists sorted based on a set of cutoff filters. A group of genes differentially regulated by CE were also identified to be antagonized by BZA when comparing CE with the BZA+CE treatment. All three SERMs showed significant antagonistic effect against CE-stimulated cell proliferation, based on the MCF-7 cell proliferation assay and GeneChip data, with the order of antagonist activity being BZA>RAL>LAS. These results indicate that SERMs in combination with CE exhibit differential pharmacology, and therefore, combinations of other SERMs and estrogen preparations may not yield the same effects that are observed in clinic by pairing BZA with CE.

The effects of tamoxifen and estradiol on myometrial differentiation and organization during early uterine development in the CD1 mouse

We used a neonatal mouse model to examine the histogenesis of uterine adenomyosis, and to test whether adenomyosis is due to an abnormality in myometrial differentiation, or in extracellular matrix proteins expression. We also studied the effects of tamoxifen and estradiol on uterine development, myometrial differentiation, and organization. Female CD1 pups were treated with oral tamoxifen (1 mg/kg) (n=27) or estradiol (0.1 mg/kg) (n=24) from age 1 to 5 days. Uteri from control (n=27) and treated mice were obtained on days 2, 5, 10, 15, and 42 of age. We examined the sections histologically, using image analysis and immunohistochemistry for alpha-smooth muscle actin (alpha-SMA), desmin, vimentin, laminin, fibronectin, and estrogen receptor-alpha. Following tamoxifen exposure, all uteri showed adenomyosis by 6 weeks of age (seen as early as day 10). The inner myometrium showed thinning, lack of continuity, disorganization, and bundling. alpha-SMA expression was normal. Desmin expression normally showed a wave of maturation that was absent in tamoxifen-treated mice. In the estradiol group, adenomyosis was not observed. All uterine layers were normally developed, but hypertrophied. The inner myometrium retained its circular arrangement. There was no difference in the localization of laminin or fibronectin between groups (laminin expression was reduced in the tamoxifen treated uteri). Vimentin could not be detected in all groups. Our results suggest that the development of the inner myometrium is particularly sensitive to estrogen antagonism, and can be affected by steroid receptors modulation. Disruption of the inner myometrium may play a role in the development of uterine adenomyosis.