The role of mesenchymal-epithelial transition in endometrial function

BACKGROUND

The human uterine endometrium undergoes significant remodeling and regeneration on a rapid and repeated basis, after parturition, menstruation, and in some cases, injury. The ability of the adult endometrium to undergo cyclic regeneration and differentiation/decidualization is essential for successful human reproduction. Multiple key physiologic functions of the endometrium require the cells of this tissue to transition between mesenchymal and epithelial phenotypes, processes known as mesenchymal-epithelial transition (MET) and epithelial-mesenchymal transition (EMT). Although MET/EMT processes have been widely characterized in embryonic development and in the context of malignancy, mounting evidence demonstrates the importance of MET/EMT in allowing the endometrium the phenotypic and functional flexibility necessary for successful decidualization, regeneration/re-epithelialization and embryo implantation.

OBJECTIVE AND RATIONALE

The objective of this review is to provide a comprehensive summary of the observations concerning MET and EMT and their regulation in physiologic uterine functions, specifically in the context of endometrial regeneration, decidualization and embryo implantation.

SEARCH METHODS

Using variations of the search terms 'mesenchymal-epithelial transition', 'mesenchymal-epithelial transformation', 'epithelial-mesenchymal transition', 'epithelial-mesenchymal transformation', 'uterus', 'endometrial regeneration', 'endometrial decidualization', 'embryo implantation', a search of the published literature between 1970 and 2018 was conducted using the PubMed database. In addition, we searched the reference lists of all publications included in this review for additional relevant original studies.

OUTCOMES

Multiple studies demonstrate that endometrial stromal cells contribute to the regeneration of both the stromal and epithelial cell compartments of the uterus, implicating a role for MET in mechanisms responsible for endometrial regeneration and re-epithelialization. During decidualization, endometrial stromal cells undergo morphologic and functional changes consistent with MET in order to accommodate embryo implantation. Under the influence of estradiol, progesterone and multiple other factors, endometrial stromal fibroblasts acquire epithelioid characteristics, such as expanded cytoplasm and rough endoplasmic reticulum required for greater secretory capacity, rounded nuclei, increased expression of junctional proteins which allow for increased cell-cell communication, and a reorganized actin cytoskeleton. During embryo implantation, in response to both maternal and embryonic-derived signals, the maternal luminal epithelium as well as the decidualized stromal cells acquire the mesenchymal characteristics of increased migration/motility, thus undergoing EMT in order to accommodate the invading trophoblast.

WIDER IMPLICATIONS

Overall, the findings support important roles for MET/EMT in multiple endometrial functions required for successful reproduction. The endometrium may be considered a unique wound healing model, given its ability to repeatedly undergo repair without scarring or loss of function. Future studies to elucidate how MET/EMT mechanisms may contribute to scar-free endometrial repair will have considerable potential to advance studies of wound healing mechanisms in other tissues.

Molecular discrimination inside polymer nanotubules

Recognition of small organic molecules and large biomolecules such as proteins is of great importance in pharmaceutical as well as biological applications. Recognition inside a nanoporous membrane is particularly attractive, because of the advantages associated with ligand-receptor interactions in confined spaces. Classical nanoporous membrane-based separations simply use the difference in size of the analytes relative to pore size in the membrane. In order to bring about selectivity beyond size, it is necessary that methods for functionalizing the membrane pores are readily available. Here, we describe a simple approach to functionalize the nanopores within these membranes using self-assembling and non-self-assembling polymers. We show that these modified membranes separate small molecules based on size, charge and hydrophobicity. We also demonstrate here that proteins can be differentially transported through the nanopores based on their size and/or electrostatics.

Novel label-free DNA sensors based on poly(3,4-ethylenedioxythiophene)Electronic Supplementary Information (ESI) available: Experimental details and sensor response for various sensors listed in Table 2. Cyclic voltammograms confirming the increase in resistance due to the duplex formation between the probe and target DNA in conducting polymer matrix. See http://www.rsc.org/suppdata/cc/b3/b316794a/

We report on the design and development of a novel label-free DNA sensor based on conducting poly(3,4-ethylenedioxythiophene) for the direct detection and quantification of target ssDNA.

Physical and psychosocial burden due to lymphatic filariasis as perceived by patients and medical experts

Patients with lymphatic filariasis (LF) face considerable physical, psychological and social disabilities. Morbidity management and control are important components of the Global Programme to Eliminate Lymphatic Filariasis. But information on the various disabilities caused by LF is scanty. We measured the severity levels of seven health states of LF in the physical and psychosocial domains of health from the perspective of patients and medical experts, using a 7-domain 5-level (7D5L) descriptive system. Adenolymphangitis had the highest severity levels in all domains of health followed by lymphoedema grade 4 (L4), lymphoedema grade 3 (L3), hydrocele grade 2 (H2), lymphoedema grade 2 (L2), lymphoedema grade1 (L1) and hydrocele grade 1 (H1). People with higher grades of lymphoedema and hydrocele had more severe psychosocial problems than physical ones. Severity levels assessed by medical experts were lower than those reported by sufferers. These findings indicate that LF has considerable impact on the physical, mental and social domains of health. Morbidity management programmes should be broadened to include counselling, rehabilitation and health education to manage the psychosocial problems caused by LF.

Inferences on the common mean of several normal populations based on the generalized variable method

This article presents procedures for hypothesis testing and interval estimation of the common mean of several normal populations. The methods are based on the concepts of generalized p-value and generalized confidence limit. The merits of the proposed methods are evaluated numerically and compared with those of the existing methods. Numerical studies show that the new procedures are accurate and perform better than the existing methods when the sample sizes are moderate and the number of populations is four or less. If the number of populations is five or more, then the generalized variable method performs much better than the existing methods regardless of the sample sizes. The generalized variable method and other existing methods are illustrated using two examples.

The dynamics ofWuchereria bancroftiinfection: a model-based analysis of longitudinal data from Pondicherry, India

This paper presents a model-based analysis of longitudinal data describing the impact of integrated vector management on the intensity ofWuchereria bancroftiinfection in Pondicherry, India. The aims of this analysis were (1) to gain insight into the dynamics of infection, with emphasis on the possible role of immunity, and (2) to develop a model that can be used to predict the effects of control. Using the LYMFASIM computer simulation program, two models with different types of immunity (anti-L3 larvae or anti-adult worm fecundity) were compared with a model without immunity. Parameters were estimated by fitting the models to data from 5071 individuals with microfilaria-density measurement before and after cessation of a 5-year vector management programme. A good fit, in particular of the convex shape of the age-prevalence curve, required inclusion of anti-L3 or anti-fecundity immunity in the model. An individual's immune-responsiveness was found to halve in ~10 years after cessation of boosting. Explanation of the large variation in Mf-density required considerable variation between individuals in exposure and immune responsiveness. The mean life-span of the parasite was estimated at about 10 years. For the post-control period, the models predict a further decline in Mf prevalence, which agrees well with observations made 3 and 6 years after cessation of the integrated vector management programme.

Are intracytoplasmic sperm injection and high serum estradiol compounding risk factors for adverse obstetric outcomes in assisted reproductive technology?

OBJECTIVE

To evaluate whether intracytoplasmic sperm injection (ICSI) use and E2 on the final day of assisted reproductive technology (ART) stimulation are associated with adverse obstetric complications related to placentation.

DESIGN

Retrospective cohort study.

SETTING

Large private ART practice.

PATIENT(S)

A total of 383 women who underwent ART resulting in a singleton live birth.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Adverse placental outcomes composed of placenta accreta, placental abruption, placenta previa, intrauterine growth restriction, preeclampsia, gestational hypertension, and small for gestational age infants.

RESULT(S)

Patients with adverse placental outcomes had higher peak serum E2 levels and were three times more likely to have used ICSI. Adverse placental outcomes were associated with increasing E2 (odds ratio 1.36, 95% confidence interval 1.13-1.65) and ICSI (odds ratio 3.86, 95% confidence interval 1.61-9.27). Adverse outcomes increased when E2 was >3,000 pg/mL and continued to increase in a linear fashion until E2 was >5,000 pg/mL. The association of ICSI with adverse outcomes was independent of male factor infertility. Interaction testing suggested the adverse effect of E2 was primarily seen in ICSI cycles, but not in conventional IVF cycles. Estradiol >5,000 pg/mL was associated with adverse placental events in 36% of all ART cycles and 52% of ICSI cycles.

CONCLUSION(S)

ICSI and elevated E2 on the day of hCG trigger were associated with adverse obstetric outcomes related to placentation. The finding of a potential interaction of E2 and ICSI with adverse placental events is novel and warrants further investigation.

The relationship between microfilarial load in the human host and uptake and development of Wuchereria bancrofti microfilariae by Culex quinquefasciatus: a study under natural conditions

The uptake of Wuchereria bancrofti microfilariae (Mf) by Culex quinquefasciatus and their development in relation to human Mf density were quantified by allowing a total of 1096 wild mosquitoes to feed on 13 volunteers sleeping under partially open bed-nets. For each volunteer, each hour between 18.00 and 06.00 h the Mf density in finger-prick blood was determined and engorged mosquitoes collected. Each hourly collection of mosquitoes was kept separately. Half of them was dissected within 18 h post-feeding for the presence of ingested Mf, the other half was reared for 12 days to allow for the development of L3 larvae. About 20% of the latter mosquitoes died during these 12 days and these harboured significantly more larvae than the surviving ones, which could be an indication of excess-mortality among heavily infected mosquitoes. Assuming that variability in Mf uptake and in the number of developed L3 larvae can be described by a negative binomial distribution, a maximum-likelihood procedure was applied to estimate the relationship between human Mf density and both the arithmetic mean Mf uptake and L3 development. Both were adequately described by a saturating hyperbolic function that significantly differed from linearity. The saturation level for Mf was estimated at 29 (CI: 20-54) and for L3 larvae at 6.6 (CI: 4.3-17.0). Next, the L3 yield was related to Mf uptake indicating that the W. bancrofti-C. quinquefasciatus complex shows 'limitation', i.e. a decreasing yield for an increasing uptake. Both the number of Mf ingested and the number of L3 larvae developing per mosquito were found to be highly aggregated, with the level of aggregation decreasing in a non-linear way with human Mf density.

A MULTIVARIATE TEST FOR SIMILARITY OF TWO DISSOLUTION PROFILES

A multivariate test of size a for assessing the similarity of two dissolution profiles is proposed. The inferential procedure is developed by using the approach for the common mean problem in a multivariate setup due to Halperin (1961). The performance of the proposed method is compared with Intersection Union Test as well as f2 criterion recommended by the FDA through a simulation study. All the methods are illustrated with real examples.