Oestradiol enhances in vitro the histamine release induced by embryonic histamine-releasing factor (EHRF) from uterine mast cells

Mechanism and clinical evidence of immunotherapy in allergic rhinitis

Allergic rhinitis is a common upper airway disease caused by hypersensitivity to various aeroallergens. It causes increased inflammation throughout the body and may be complicated by other otolaryngological pathologies such as chronic hyperplastic eosinophilic sinusitis, nasal polyposis, and serous otitis media. Allergic rhinitis is an IgE-mediated disease and immunotherapy can be a possible approach for patients to limit the use of antihistamines and corticosteroids. There is evidence that allergen immunotherapy can prevent the development of new sensitizations and reduce the risk of later development of asthma in patients with allergic rhinitis. However, some patients do not benefit from this approach and the efficacy of immunotherapy in reducing the severity and relapse of symptoms is still a matter of debate. This review highlights new aspects of allergic rhinitis with a particular focus on the impact of sexual dimorphism on the disease manifestation and efficacy to the allergen specific immunotherapy.

Using a Quantitative High-Throughput Screening Platform to Identify Molecular Targets and Compounds as Repurposing Candidates for Endometriosis

Endometriosis, defined as the growth of hormonally responsive endometrial-like tissue outside of the uterine cavity, is an estrogen-dependent, chronic, pro-inflammatory disease that affects up to 11.4% of women of reproductive age and gender-diverse people with a uterus. At present, there is no long-term cure, and the identification of new therapies that provide a high level of efficacy and favourable long-term safety profiles with rapid clinical access are a priority. In this study, quantitative high-throughput compound screens of 3517 clinically approved compounds were performed on patient-derived immortalized human endometrial stromal cell lines. Following assay optimization and compound criteria selection, a high-throughput screening protocol was developed to enable the identification of compounds that interfered with estrogen-stimulated cell growth. From these screens, 23 novel compounds were identified, in addition to their molecular targets and in silico cell-signalling pathways, which included the neuroactive ligand-receptor interaction pathway, metabolic pathways, and cancer-associated pathways. This study demonstrates for the first time the feasibility of performing large compound screens for the identification of new translatable therapeutics and the improved characterization of endometriosis molecular pathophysiology. Further investigation of the molecular targets identified herein will help uncover new mechanisms involved in the establishment, symptomology, and progression of endometriosis.

Interactions between Macrophages and Mast Cells in the Female Reproductive System

Mast cells (MCs) and macrophages (Mϕs) are innate immune cells that differentiate from early common myeloid precursors and reside in all body tissues. MCs have a unique capacity to neutralize/degrade toxic proteins, and they are hypothesized as being able to adopt two alternative polarization profiles, similar to Mϕs, with distinct or even opposite roles. Mϕs are very plastic phagocytic cells that are devoted to the elimination of senescent/anomalous endogenous entities (to maintain tissue homeostasis), and to the recognition and elimination of exogenous threats. They can adopt several functional phenotypes in response to microenvironmental cues, whose extreme profiles are the inflammatory/killing phenotype (M1) and the anti-inflammatory/healing phenotype (M2). The concomitant and abundant presence of these two cell types and the partial overlap of their defensive and homeostatic functions leads to the hypothesis that their crosstalk is necessary for the optimal coordination of their functions, both under physiological and pathological conditions. This review will examine the relationship between MCs and Mϕs in some situations of homeostatic regulation (menstrual cycle, embryo implantation), and in some inflammatory conditions in the same organs (endometriosis, preeclampsia), in order to appreciate the importance of their cross-regulation.

Nuclear Receptors in Asthma: Empowering Classical Molecules Against a Contemporary Ailment

The escalation in living standards and adoption of 'Western lifestyle' has an allied effect on the increased allergy and asthma burden in both developed and developing countries. Current scientific reports bespeak an association between allergic diseases and metabolic dysfunction; hinting toward the critical requirement of organized lifestyle and dietary habits. The ubiquitous nuclear receptors (NRs) translate metabolic stimuli into gene regulatory signals, integrating diet inflences to overall developmental and physiological processes. As a consequence of such promising attributes, nuclear receptors have historically been at the cutting edge of pharmacy world. This review discusses the recent findings that feature the cardinal importance of nuclear receptors and how they can be instrumental in modulating current asthma pharmacology. Further, it highlights a possible future employment of therapy involving dietary supplements and synthetic ligands that would engage NRs and aid in eliminating both asthma and linked comorbidities. Therefore, uncovering new and evolving roles through analysis of genomic changes would represent a feasible approach in both prevention and alleviation of asthma.

Human Chorionic Gonadotropin-Mediated Immune Responses That Facilitate Embryo Implantation and Placentation

Human chorionic gonadotropin (hCG) serves as one of the first signals provided by the embryo to the mother. Exactly at the time when the first step of the implantation process is initiated and the blastocyst adheres to the maternal endometrium, the embryonic tissue starts to actively secrete hCG. Shortly thereafter, the hormone can be detected in the maternal circulation where its concentration steadily increases throughout early pregnancy as it is continuously released by the forming placenta. Accumulating evidence underlines the critical function of hCG for embryo implantation and placentation. hCG not only regulates biological aspects of these early pregnancy events but also supports maternal immune cells in their function as helpers in the establishment of an adequate embryo-endometrial relationship. In view of its early presence in the maternal circulation, hCG has the potential to influence both local uterine immune cell populations as well as peripheral ones. The current review aims to summarize recent literature on the participation of innate and adaptive immune cells in embryo implantation and placentation with a specific focus on their regulation by hCG.

Impact of allergic diseases on fertility

The incidence of allergic diseases has been increasing in recent decades, and currently, nearly 30% of the European population suffer from some type of allergy. Also, an increasing number of people are suffering from infertility. Both diseases are related to the hormonal and immune systems, which prompts the question as to whether there is a causal relationship between allergic disorders and the reproductive system. The purpose of this review is to evaluate whether there is a link between allergic diseases and infertility, using the available literature.

Immune Tumor Microenvironment in Breast Cancer and the Participation of Estrogen and Its Receptors in Cancer Physiopathology

Breast cancer is characterized by cellular and molecular heterogeneity. Several molecular events are involved in controlling malignant cell process. In this sense, the importance of studying multiple cell alterations in this pathology is overriding. A well-identified fact on immune response is that it can vary depend on sex. Steroid hormones and their receptors may regulate different functions and the responses of several subpopulations of the immune system. Few reports are focused on the function of estrogen receptors (ERs) on immune cells and their roles in different breast cancer subtypes. Thus, the aim of this review is to investigate the immune infiltrating tumor microenvironment and prognosis conferred by it in different breast cancer subtypes, discuss the current knowledge and point out the roles of estrogens and its receptors on the infiltrating immune cells, as well as to identify how different immune subsets are modulated after anti-hormonal treatments in breast cancer patients.

The Impact of Sex and Age on the Prevalence of Clinically Relevant Sensitization and Asymptomatic Sensitization in the General Population

The objective of our study was to evaluate the impact of sex and age on the prevalence of sensitization to inhalant allergens. The study was performed as a part of Polish Epidemiology of Allergic Diseases study, and data concerning citizens of Wroclaw were analyzed. The participants were divided into three age groups (6-7, 13-14, and 20-44 years) with a subdivision according to sex. We randomly selected 1409 individuals, 439 people complied; the complete set of tests was performed on 421 of them. We found that 37.7 % of the study population demonstrated sensitization to at least one of the allergens tested. Positive skin tests were found more frequently in males than in females (p = 0.003); among 6-7-year-old children, the sensitization was independent of sex (p = 0.26), while in two other groups, it was higher in males (p = 0.002 and p = 0.03, respectively). Clinically asymptomatic sensitization (AS) was found more often in females than in males (p = 0.04). The higher rate of AS in women was observed only in the two younger age groups, while in the 20-44-year-old group AS did not differ between the sexes (p = 0.72). Female sex hormones may contribute to a later change in the nature of sensitization from clinically asymptomatic to symptomatic. Further studies are needed to confirm the results of our study.

Cellular Regulation of the Uterine Microenvironment That Enables Embryo Implantation

Implantation of the fertilized egg into the maternal uterus is a crucial step in pregnancy establishment. Increasing evidence suggests that its success depends on various cell types of the innate immune system and on the fine balance between inflammatory and anti-inflammatory processes. In addition, it has recently been established that regulatory T cells play a superordinate role in dictating the quality of uterine environment required for successful pregnancy. Here, we discuss the cellular regulation of uterine receptivity with emphasis on the function and regulation of cells from the innate and adaptive immune system.

Soluble ligands and their receptors in human embryo development and implantation

Extensive evidence suggests that soluble ligands and their receptors mediate human preimplantation embryo development and implantation. Progress in this complex area has been ongoing since the 1980s, with an ever-increasing list of candidates. This article specifically reviews evidence of soluble ligands and their receptors in the human preimplantation stage embryo and female reproductive tract. The focus will be on candidates produced by the human preimplantation embryo and those eliciting developmental responses in vitro, as well as endometrial factors related to implantation and receptivity. Pathways to clinical translation, including innovative diagnostics and other technologies, are also highlighted, drawing from this collective evidence toward facilitating joint improvements in embryo quality and endometrial receptivity. This strategy could not only benefit clinical outcomes in reproductive medicine but also provide broader insights into the peri-implantation period of human development to improve fetal and neonatal health.

Endocrine factors modulating immune responses in pregnancy

How the semi-allogeneic fetus is tolerated by the maternal immune system remains a fascinating phenomenon. Despite extensive research activity in this field, the mechanisms underlying fetal tolerance are still not well understood. However, there are growing evidences that immune–immune interactions as well as immune–endocrine interactions build up a complex network of immune regulation that ensures fetal survival within the maternal uterus. In the present review, we aim to summarize emerging research data from our and other laboratories on immune modulating properties of pregnancy hormones with a special focus on progesterone, estradiol, and human chorionic gonadotropin. These pregnancy hormones are critically involved in the successful establishment, maintenance, and termination of pregnancy. They suppress detrimental maternal alloresponses while promoting tolerance pathways. This includes the reduction of the antigen-presenting capacity of dendritic cells (DCs), monocytes, and macrophages as well as the blockage of natural killer cells, T and B cells. Pregnancy hormones also support the proliferation of pregnancy supporting uterine killer cells, retain tolerogenic DCs, and efficiently induce regulatory T (Treg) cells. Furthermore, they are involved in the recruitment of mast cells and Treg cells into the fetal–maternal interface contributing to a local accumulation of pregnancy-protective cells. These findings highlight the importance of endocrine factors for the tolerance induction during pregnancy and encourage further research in the field.

Food-dependent exercise-induced anaphylaxis: is wheat unique?

This review draws comparisons between wheat-dependent exercise-induced anaphylaxis (WDEIA) and other food-dependent exercise-induced anaphylaxis (FDEIAs) and discusses the importance of co-factors in its pathophysiology. FDEIA remains an enigmatic condition since it was first described 30 years ago. The sporadic and unpredictable nature of its reactions has puzzled clinicians and scientists for decades, but recent studies on WDEIA have enlightened us about the pathophysiology of this condition. The identification of defined allergic epitopes such as Tri a 19, α-gliadin, β-gliadin and γ-gliadin in WDEIA enables it to become the perfect model for studying FDEIA, but WDEIA is by no means a unique condition. On a larger scale, FDEIA represents a crucial link between IgE-mediated and anaphylactoid reactions and provides supportive evidence for the concept of 'summation anaphylaxis' and the need to overcome the 'allergen threshold'. Future work should focus on identifying more of the FDEIA epitopes and understanding their distinct molecular properties. The development of a biomarker in order to identify patients susceptible to co-factor influences would be invaluable.

Progesterone induces mucosal immunity in a rodent model of human taeniosis by Taenia solium

More than one quarter of human world's population is exposed to intestinal helminth parasites. The Taenia solium tapeworm carrier is the main risk factor in the transmission of both human neurocysticercosis and porcine cysticercosis. Sex steroids play an important role during T. solium infection, particularly progesterone has been proposed as a key immunomodulatory hormone involved in susceptibility to human taeniosis in woman and cysticercosis in pregnant pigs. Thus, we evaluated the effect of progesterone administration upon the experimental taeniosis in golden hamsters (Mesocricetus auratus). Intact female adult hamsters were randomly divided into 3 groups: progesterone-subcutaneously treated; olive oil-treated as the vehicle group; and untreated controls. Animals were treated every other day during 4 weeks. After 2 weeks of treatment, all hamsters were orally infected with 4 viable T. solium cysticerci. After 2 weeks post infection, progesterone-treated hamsters showed reduction in adult worm recovery by 80%, compared to both vehicle-treated and non-manipulated infected animals. In contrast to control and vehicle groups, progesterone treatment diminished tapeworm length by 75% and increased proliferation rate of leukocytes from spleen and mesenteric lymph nodes of infected hamsters by 5-fold. The latter exhibited high expression levels of IL-4, IL-6 and TNF-α at the duodenal mucosa, accompanied with polymorphonuclear leukocytes infiltration. These results support that progesterone protects hamsters from the T. solium adult tapeworm establishment by improving the intestinal mucosal immunity, suggesting a potential use of analogues of this hormone as novel inductors of the gut immune response against intestinal helminth infections and probably other bowel-related disorders.

Distribution of mast cells in vaginal, cervical and uterine tissue of non-pregnant mares: investigations on correlations with ovarian steroids

Mast cells constitute part of the cellular immune system of the genital tract. They play a potential role in cervical remodelling during parturition and are subject to the influence of ovarian steroids. In this study, the influence of oestradiol-17β and progesterone on the distribution of mast cells in equine vaginal, cervical and uterine tissue was evaluated. Genital tracts were retrieved from healthy mares at a local slaughterhouse. The cervix was divided along the longitudinal axis into five equivalent regions from cranial to caudal (R1 to R5). Toluidine blue staining was used for the detection of mast cells. Hormone values were determined via radioimmunoassay. In cervical tissue, mast cells were present at higher frequency and higher density than in vaginal and uterine tissue. Statistically significant differences were obtained between cervical R1 (cranial) and uterus as well as cervical R2 and uterus (p < 0.05). In cervical tissue, an association between the presence of mast cells and peripheral oestrogen concentrations was observed, whereas such correlation could not be established for vaginal and uterine tissue. With increasing oestradiol-17β concentrations, the density of mast cells in cervical tissue increased to a statistically significant degree in the cranial (r = 0.46; p = 0.05) and caudal (r = 0.5; p = 0.03) regions. We propose that mast cells play a role in the cyclic remodelling of the equine cervix during the course of the oestrous cycle. Elucidation of mechanisms controlling cervical remodelling could contribute to development of therapies for mares showing a lack in cervical opening during oestrus.

Estradiol and progesterone regulate the migration of mast cells from the periphery to the uterus and induce their maturation and degranulation

BACKGROUND

Mast cells (MCs) have long been suspected as important players for implantation based on the fact that their degranulation causes the release of pivotal factors, e.g., histamine, MMPs, tryptase and VEGF, which are known to be involved in the attachment and posterior invasion of the embryo into the uterus. Moreover, MC degranulation correlates with angiogenesis during pregnancy. The number of MCs in the uterus has been shown to fluctuate during menstrual cycle in human and estrus cycle in rat and mouse indicating a hormonal influence on their recruitment from the periphery to the uterus. However, the mechanisms behind MC migration to the uterus are still unknown.

METHODOLOGY/PRINCIPAL FINDINGS

We first utilized migration assays to show that MCs are able to migrate to the uterus and to the fetal-maternal interface upon up-regulation of the expression of chemokine receptors by hormonal changes. By using a model of ovariectomized animals, we provide clear evidences that also in vivo, estradiol and progesterone attract MC to the uterus and further provoke their maturation and degranulation.

CONCLUSION/SIGNIFICANCE

We propose that estradiol and progesterone modulate the migration of MCs from the periphery to the uterus and their degranulation, which may prepare the uterus for implantation.

Female sex hormones mediate the allergic lung reaction by regulating the release of inflammatory mediators and the expression of lung E-selectin in rats

Background

Fluctuations of estradiol and progesterone levels caused by the menstrual cycle worsen asthma symptoms. Conflicting data are reported in literature regarding pro and anti-inflammatory properties of estradiol and progesterone.

Methods

Female Wistar rats were ovalbumin (OVA) sensitized 1 day after resection of the ovaries (OVx). Control group consisted of sensitized-rats with intact ovaries (Sham-OVx). Allergic challenge was performed by aerosol (OVA 1%, 15 min) two weeks later. Twenty four hours after challenge, BAL, bone marrow and total blood cells were counted. Lung tissues were used as explants, for expontaneous cytokine secretion in vitro or for immunostaining of E-selectin.

Results

We observed an exacerbated cell recruitment into the lungs of OVx rats, reduced blood leukocytes counting and increased the number of bone marrow cells. Estradiol-treated OVx allergic rats reduced, and those treated with progesterone increased, respectively, the number of cells in the BAL and bone marrow. Lungs of OVx allergic rats significantly increased the E-selectin expression, an effect prevented by estradiol but not by progesterone treatment. Systemically, estradiol treatment increased the number of peripheral blood leukocytes in OVx allergic rats when compared to non treated-OVx allergic rats. Cultured-BAL cells of OVx allergic rats released elevated amounts of LTB₄ and nitrites while bone marrow cells increased the release of TNF-α and nitrites. Estradiol treatment of OVx allergic rats was associated with a decreased release of TNF-α, IL-10, LTB₄ and nitrites by bone marrow cells incubates. In contrast, estradiol caused an increase in IL-10 and NO release by cultured-BAL cells. Progesterone significantly increased TNF- α by cultured BAL cells and bone marrow cells.

Conclusions

Data presented here suggest that upon hormonal oscillations the immune sensitization might trigger an allergic lung inflammation whose phenotype is under control of estradiol. Our data could contribute to the understanding of the protective role of estradiol in some cases of asthma symptoms in fertile ans post-menopausal women clinically observed.

Advances in mast cell biology: new understanding of heterogeneity and function

Mast cells are classically viewed as effector cells of IgE-mediated allergic diseases. However, over the last decade our understanding has been enriched about their roles in host defense, innate and adaptive immune responses, and in homeostatic responses, angiogenesis, wound healing, tissue remodeling, and immunoregulation. Despite impressive progress, there are large gaps in our understanding of their phenotypic heterogeneity, regulatory mechanisms involved, and functional significance. This review summarizes our knowledge of mast cells in innate and acquired immunity, allergic inflammation and tissue homeostasis, as well as some of the regulatory mechanisms that control mast cell development, phenotypic determination, and function, particularly in the context of mucosal surfaces.

Gender difference, sex hormones, and immediate type hypersensitivity reactions

Gender differences in the development and prevalence of human diseases have long been recognized. Immense interest grows in the understanding of the role of sex hormones in the homeostasis of immunity. Asthma predominates in boys before puberty and this gender preference reverses after puberty and in adulthood, when adult women tend to have a more severe disease, often recalcitrant to treatment. Atopic eczema in preschool children shows insignificant gender difference or male preponderance in different studies, with more adult females suffering from atopic eczema. The limited data on the prevalence of immediate hypersensitivity to hymenoptera venom show controversial results. Discrepancy exists regarding the gender difference in food allergy, with females reporting significantly more allergic reactions in questionnaire studies. In general, adverse reactions to nonionic iodinated radiocontrast media are more commonly observed in females. The course of allergic diseases varies unpredictably during pregnancy, whereas hormone replacement therapy in postmenopausal women usually has a favorable influence on the course of asthma. Experiments in rodents confirm an effect of estrogens on mast cell activation and allergic sensitization, while progesterone is shown to suppress histamine release but potentiate IgE induction. Dehydroepiandrosterone may antagonize the production of Th2 cytokines but the effect of testosterone and the other androgens remains less defined. Actual data from human studies are lacking.

Gender-medicine aspects in allergology

Despite the identical immunological mechanisms activating the release of mediators and consecutive symptoms in immediate-type allergy, there is still a clear clinical difference between female and male allergic patients. Even though the risk of being allergic is greater for boys in childhood, almost from adolescence onwards it seems to be a clear disadvantage to be a woman as far as atopic disorders are concerned. Asthma, food allergies and anaphylaxis are more frequently diagnosed in females. In turn, asthma and hay fever are associated with irregular menstruation. Pointing towards a role of sex hormones, an association of asthma and intake of contraceptives, and a risk for asthma exacerbations during pregnancy have been observed. Moreover, peri- and postmenopausal women were reported to increasingly suffer from asthma, wheeze and hay fever, being even enhanced by hormone replacement therapy. This may be on account of the recently identified oestradiol-receptor-dependent mast-cell activation. As a paradox of nature, women may even become hypersensitive against their own sex hormones, resulting in positive reactivity upon intradermal injection of oestrogen or progesterone. More importantly, this specific hypersensitivity is associated with recurrent miscarriages. Even though there is a striking gender-specific bias in IgE-mediated allergic diseases, public awareness of this fact still remains minimal today.

Distribution and heterogeneity of mast cells in female reproductive tract and ovary on different days of the oestrus cycle in Angora goats

The physiological distribution of mast cells (MCs) in the reproductive tract and ovary of 12 Angora goats was determined using light microscopic histochemical techniques. Uterus (corpus uteri and cornu uteri), uterine cervix, uterine tubes (isthmus and ampulla) and ovary samples were obtained by laparatomy from groups of animals during metoestrus, dioestrus and proestrus (days 5, 10 and 16 of the oestrous cycle). Tissues were fixed in Mota's fixative (basic lead acetate) for 48 h and embedded in paraffin. Six-micrometre-thick sections were stained with toluidine blue in 1% aqueous solution at pH 1.0 for 5 min and alcian blue-Safranin at pH 1.0 for 30 min. MCs were generally associated with blood vessels in all reproductive organs. In the uterus, they were concentrated mainly in the close of the uterine gland and deep stroma in the endometrium. Higher MC numbers were observed by toluidine blue staining in the uterus, uterine cervix and uterine tubes on days 10 (corpus uterine: 4.7 +/- 3.8 and cornu uterine: 4.9 +/- 3.5) and 16 (corpus uterine: 5.9 +/- 4.5 and cornu uterine: 5.4 +/- 2.4) of the oestrous cycle compared with day 5 (p < 0.05). Mast cells were not observed in the follicles, the corpus luteum and the underside of the surface epithelium of the ovarian cortex, but were observed in the interstitial cortical stroma and the ovarian medulla. In the ovary, MC numbers were significantly higher on day 16 of the oestrous cycle (cortex: 3.4 +/- 2.4 and medulla: 5.7 +/- 4.5, p < 0.05). Safranin-positive connective tissue MCs were not observed in the uterine tube on any occasion. These results indicate oestrous cycle-related changes in the number and location of MCs in goat reproductive organs.

Cellular recruitment and cytokine generation in a rat model of allergic lung inflammation are differentially modulated by progesterone and estradiol

We evaluated the role of estradiol and progesterone in allergic lung inflammation. Rats were ovariectomized (Ovx) and, 7 days later, were sensitized with ovalbumin (OA) and challenged after 2 wk with inhaled OA; experiments were performed 1 day thereafter. Ovx-allergic rats showed reduced cell recruitment into the bronchoalveolar lavage (BAL) fluid relative to sham-Ovx allergic rats, as was observed in intact allergic rats treated with ICI-182,780. Estradiol increased the number of cells in the BAL of Ovx-allergic rats, whereas progesterone induced an additional reduction. Cells of BAL and bone marrow (BM) of Ovx-allergic rats released elevated amounts of IL-10 and reduced IL-1beta and TNF-alpha. BM cells of Ovx-allergic rats released increased amounts of IL-10 and lower amounts of IL-4. Estradiol treatment of Ovx-allergic rats decreased the release of IL-10 but increased that of IL-4 by BM cells. Estradiol also caused an increased release of IL-1beta and TNF-alpha by BAL cells. Progesterone significantly increased the release of IL-10, IL-1beta, and TNF-alpha by BAL cells and augmented that of IL-4 by BM cells. Degranulation of bronchial mast cells from Ovx rats was reduced after in vitro challenge, an effect reverted by estradiol but not by progesterone. We suggest that the serum estradiol-to-progesterone ratio might drive cellular recruitment, modulating the pulmonary allergy and profile of release of anti-inflammatory or inflammatory cytokines. The existence of such dual hormonal effects suggests that the hormone therapy of asthmatic postmenopausal women and of those suffering of premenstrual asthma should take into account the possibility of worsening the pulmonary conditions.

Uterine Temporal Response to Acute Exposure to 17α-Ethinyl Estradiol in the Immature Rat

The rat uterus responds to acute estrogen treatment with a series of well-characterized physiological responses; however, the gene expression changes required to elicit these responses have not been fully characterized. In order to understand early events induced by estrogen exposure in vivo, we evaluated the temporal gene expression in the uterus of the immature rat after a single dose of 17 alpha-ethinyl estradiol (EE) by microarray analysis, evaluating the expression of 15,923 genes. Immature 20-day-old rats were exposed to a single dose of EE (10 microg/kg), and the effects on uterine histology, weight, and gene expression were determined after 1, 2, 8, 24, 48, 72, and 96 h. EE induced changes in the expression of 3867 genes, at least at one time point (p < or = 0.0001), and at least 1.5-fold (up- or downregulated). Specifically, the expression of 8, 116, 3030, 2076, 381, 445, and 125 genes was modified at 1, 2, 8, 24, 48, 72, or 96 h after exposure to EE, respectively (p < or = 0.0001, t-test). At the tissue and organ level, a clear uterotrophic response was elicited by EE after only 8 h, reaching a maximum after 24 h and remaining detectable even after 96 h of exposure. The uterine phenotypic changes were induced by sequential changes in the transcriptional status of a large number of genes, in a program that involves multiple molecular pathways. Using the Gene Ontology to better understand the temporal response to estrogen exposure, we determined that the earliest changes were in the expression of genes whose products are involved in transcriptional regulation and signal transduction, followed by genes implicated in protein synthesis, energy utilization, solute transport, cell proliferation and differentiation, tissue remodeling, and immunological responses among other pathways. The compendium of genes here presented represents a comprehensive compilation of estrogen-responsive genes involved in the uterotrophic response.

Estradiol activates mast cells via a non-genomic estrogen receptor-alpha and calcium influx

BACKGROUND

Allergic airway diseases are more common in females than in males during early adulthood. A relationship between female hormones and asthma prevalence and severity has been suggested, but the cellular and molecular mechanisms are not understood.

OBJECTIVE

To elucidate the mechanism(s) by which estrogens enhance the synthesis and release of mediators of acute hypersensitivity.

METHODS

Two mast cell/basophil cell lines (RBL-2H3 and HMC-1) and primary cultures of bone marrow derived mast cells, all of which naturally express estrogen receptor-alpha, were examined. Cells were incubated with physiological concentrations of 17-beta-estradiol with and without IgE and allergens. Intracellular Ca(2+) concentrations and the release of beta-hexosaminidase and leukotriene C(4) were quantified.

RESULTS

Estradiol alone induced partial release of the preformed, granular protein beta-hexosaminidase from RBL-2H3, BMMC and HMC-1, but not from BMMC derived from estrogen receptor-alpha knock-out mice. The newly synthesized LTC(4) was also released from RBL-2H3. Estradiol also enhanced IgE-induced degranulation and potentiated LTC(4) production. Intracellular Ca(2+) concentration increased prior to and in parallel with mediator release. Estrogen receptor antagonists or Ca(2+) chelation inhibited these estrogenic effects.

CONCLUSION

Binding of physiological concentrations of estradiol to a membrane estrogen receptor-alpha initiates a rapid onset and progressive influx of extracellular Ca(2+), which supports the synthesis and release of allergic mediators. Estradiol also enhances IgE-dependent mast cell activation, resulting in a shift of the allergen dose response.

Lymphocyte subsets and mitogen stimulation of blood lymphocytes in preeclampsia

PROBLEM

The question of whether there are differences in systemic immune reactivity in severe preeclampsia compared with normal pregnancy was addressed.

METHOD OF STUDY

During the third trimester, blood samples were taken from 12 pregnant women with severe preeclampsia. Five of the preeclamptic pregnancies were analyzed separately because they were treated with dexamethasone before the blood samples were taken. The seven dexamethasone-treated preeclamptic pregnant women were analyzed and compared with six uncomplicated pregnancies. A control group consisted of 15 nonpregnant females. Lymphocyte subsets were identified by flow cytometry. The function of peripheral blood mononuclear cells (PBMCs) was studied as proliferative responses to mitogens alone and in combination with immunomodulating drugs.

RESULTS

An increased number of B lymphocytes (CD19+) (P < 0.05) and natural killer (NK) cells (P < 0.05) was noticed in severe preeclampsia compared with normal pregnancy. The proliferative response of PBMCs in phytohemagglutinin (PHA)-stimulated cultures in autologous serum from patients with severe preeclampsia was reduced (P < 0.05) compared with normal pregnancy. The addition of indomethacin and cimetidine significantly stimulated (P < 0.05) the proliferative responses. The enhancing effect of cimetidine was not found in dexamethasone-treated preeclamptic patients.

CONCLUSIONS

The presence of systemic immunosuppression in severe preeclampsia is demonstrated as a reduced proliferative response of PBMCs to PHA, which could be partly restituted by indomethacin or cimetidine, indicating immunosuppressor activity that is mediated by prostaglandin and histamine. Increased levels of B lymphocytes and NK cells were also noticed.

Inhibitory effect of neuraminidase on SP-induced histamine release and TNF-alpha mRNA in rat mast cells: evidence of a receptor-independent mechanism

The neuropeptide substance P (SP) is a mediator of neuro-inflammation and can play a role by induction of histamine release (HR) and TNF-alpha. However, its effect on the heterogeneous response of mast cells (MC) has not been completely studied. We have established that the SR can induce 25% of HR in highly purified rat uterine MC at diestrous but not at proestrous phases of the reproductive cycle and 88% of HR in peritoneal mast cells (PMC). We also found 2.2 fold increase in TNF-alpha mRNA at diestrous, in SP stimulated uterine MC versus control and 2.7 fold increase in PMC; RT and competitive PCR were used to amplify the TNF-alpha mRNA. We have thereafter investigated the mechanism whereby the binding of SP to sialic acid on the MC membrane, could trigger secretion of histamine and induction of TNF-alpha mRNA. The neuraminidase pretreatment (0.1 U/ml) inhibited SP-stimulated HR from either uterine MC and PMC (98% and 50%, respectively) and totally inhibited SP-stimulated TNF-alpha mRNA levels. The neuraminidase effect was not toxic, since it was not observed in IgE mediated HR and TNF-alpha mRNA levels. In conclusion, the inhibitory effect of the neuraminidase on the SP-mediated increase of histamine and TNF-alpha mRNA, suggests that the SP-sialic acid interaction could have a role in the MC heterogeneous response.

On the mechanism of action of ethodin in inducing myometrium contractions

1. Ethodin (Rivanol, 6,9-diamino-2-oxyethyl acridine lactate), has been described as an effective drug to induce uterine contractions similar to those in a physiologic labor in still-birth with uterine inertia. We investigate the mechanisms involved in the effect of this compound in contracting the smooth-muscle cells of the myometrium to improve our understanding of the processes involved in the onset of labor. 2. We conclude that the contractile effect of ethodin is mediated through the activation of uterine mast cells that release mediators able to contract the myometrium.

Sex steroid hormones and macrophage function

Macrophages are versatile cells whose activities are programmed by environmental signals. In this review, we discuss the potential impact of sex steroid hormones on macrophage activation and production of various effector molecules. The evidence accumulated to date supports the postulate that estrogens, progesterone, androgens and testosterone profoundly influence host defense by controlling the ability of macrophages to participate in immune responses.

Effect of substance P on uterine mast cell cytokine release during the reproductive cycle

There is increasing evidence that neuropeptides, steroid hormones and inflammatory cytokines influence the immune response during the reproductive cycle. In the present study, we focus on the effects of neuropeptide Substance P (SP) during the pre-implantation stage of embryo development (day 4 of pregnancy), at pro-estrus and di-estrus (two phases with different hormonal states). We found heterogeneous responses to SP and anti-IgE by the rat uterine mast cells (MCs), as detected by ELISA. In fact, MCs purified from uteri on day 4 of pregnancy released histamine, granulocyte macrophage-colony stimulating factor (GM-CSF) and tumor necrosis factor-alpha (TNF-alpha) in response to anti-IgE, but not to SP. When pre-incubated with SP, the release to anti-IgE was significantly enhanced compared to anti-IgE alone. Exposure of SP to antibodies to SP, prior to pre-incubation with MCs, negated the SP effect on IgE-mediated release. At the pro-estrus phase SP showed similar behavior as on day 4 of pregnancy, whereas at the di-estrus phase SP alone was capable of inducing release of histamine and cytokines from purified uterine MCs. Moreover, non-quantitative RT-PCR analysis of the TNF-alpha mRNA level suggested an SP stimulation at the di-estrus phase, but neither on day 4 of pregnancy nor at the pro-estrus phase. Taken together, these data strongly suggest that SP can modulate IgE-mediated uterine MC release of histamine and inflammatory cytokines in different ways, depending on the phase of the reproductive cycle.