Uterine Eosinophilia Research Articles

Protective role of IL33 signaling in negative pregnancy outcomes associated with lipopolysaccharide exposure.

Interleukin 33 (IL33) signaling has been implicated in the establishment and maintenance of pregnancy and in pregnancy disorders. The goal of this project was to evaluate the role of IL33 signaling in rat pregnancy. The rat possesses hemochorial placentation with deep intrauterine trophoblast invasion; features also characteristic of human placentation. We generated and characterized a germline mutant rat model for IL33 using CRISPR/Cas9 genome editing. IL33 deficient rats exhibited deficits in lung responses to an inflammatory stimulus (Sephadex G-200) and to estrogen-induced uterine eosinophilia. Female rats deficient in IL33 were fertile and exhibited pregnancy outcomes (gestation length and litter size) similar to wild-type rats. Placental weight was adversely affected by the disruption of IL33 signaling. A difference in pregnancy-dependent adaptations to lipopolysaccharide (LPS) exposure was observed between wild-type and IL33 deficient pregnancies. Pregnancy in wild-type rats treated with LPS did not differ significantly from pregnancy in vehicle-treated wild-type rats. In contrast, LPS treatment decreased fetal survival rate, fetal and placental weights, and increased fetal growth restriction in IL33 deficient rats. In summary, a new rat model for investigating IL33 signaling has been established. IL33 signaling participates in the regulation of placental development and protection against LPS-induced fetal and placental growth restriction.

Daidzein–Estrogen Interaction in the Rat Uterus and Its Effect on Human Breast Cancer Cell Growth

Sex hormone replacement therapy provides several advantages in the quality of life for climacteric women. However, estrogen-induced cell proliferation in the uterus and mammary gland increases the risk of cancer development in these organs. The lower incidence of mammary cancer in Asian women as compared with Western women has been attributed to high intake of soy isoflavones, including genistein. We have previously shown that genistein induces an estradiol-like hypertrophy of uterine cells, but does not induce cell proliferation, uterine eosinophilia, or endometrial edema. It also inhibits estradiol-induced mitosis in uterine cells and hormone-induced uterine eosinophilia and endometrial edema. Nevertheless, genistein stimulates growth of human breast cancer cells in culture; therefore, it is not an ideal estrogen for use in hormone replacement therapy (HRD). The present study investigated the effect of another soy isoflavone, daidzein (subcutaneous, 0.066 mg/kg body weight), in the same animal model, and its effect on responses induced by subsequent treatment (1 h later) with estradiol-17β (E(2); subcutaneous, 0.33 mg/kg body weight). In addition, we investigated the effects of daidzein (1 μg/mL) or E(2) on the growth of human breast cancer cells in culture. Results indicate that daidzein stimulates growth of breast cancer cells and potentiates estrogen-induced cell proliferation in the uterus. We suggest caution for the use of daidzein or formulas containing this compound in HRD. Future research strategies should be addressed in the search for new phytoestrogens that selectively inhibit cell proliferation in the uterus and breast.

Genistein Selectively Inhibits Estrogen-Induced Cell Proliferation and Other Responses to Hormone Stimulation in the Prepubertal Rat Uterus

Sex hormone replacement therapy helps improve quality of life in climacteric women. However, estrogen-induced cell proliferation in the uterus and mammary gland increases the risk for cancer in these organs. The lower incidence of mammary cancer in Asian women than in western women has been attributed to high intake of soy isoflavones, including genistein. Our previous work in the prepubertal rat uterus model showed that genistein (0.5 mg/kg body weight subcutaneously) caused an estradiol-like hypertrophy in myometrial and uterine luminal epithelial cells and an increase in RNA content in luminal epithelium; however, it did not induce cell proliferation, uterine eosinophilia, or endometrial edema. The present study investigated, in the same animal model, the effect of genistein administration (0.5 mg/kg body weight subcutaneously) before treatment with estradiol-17β (0.33 mg/kg body weight subcutaneously) on uterine responses that were not induced by genistein. Pretreatment with this phytoestrogen completely inhibited estradiol-induced mitoses in uterine luminal epithelium, endometrial stroma, and myometrium and partially inhibited estradiol-induced uterine eosinophilia and endometrial edema. These findings indicate that genistein protects against estrogen-induced cell proliferation in the uterus and suggest that future studies should investigate the possibility of using this agent to decrease the risk for uterine cancer after hormone replacement therapy in climacteric women.

Efectos de exposición aguda a cadmio en la acción de estrógenos en útero de rata impúber

Background: Few information is available about uterine effects of Cadmium (Cd) exposure, where toxic agents affecting the female genital tract interact with estrogen (E) receptors, modifiying myometrial activity and the menstrual cycle, causing dysmenorrhea, infertility and spontaneous abortion. No information exists whether prenatal or early postnatal exposure may cause any gynecologic persistent adverse effect. Our finding of a second mechanism of E interaction and differences between E receptors in the various uterine cell types suggests that Cd may affect differently E interaction in each cell-type. Objective: Evaluate a possible selective effect of acute Cd exposure on E action in the uterus during prepuber age. Method: Female prepuber rats exposed to Cd 4 mg/kg and 2 hours later, treated with Estradiol-17 2 0,3 mg/kg. A myometrial sample was obtained under anesthesia 24 hours after E treatment and histologically processed for the quantification of E responses on different uterine cell-types. Results: Cd exposure potentiates E-induced uterine eosinophilia and endometrial edema and inhibits E-induced cell hypertrophy in circular myometrium and cell proliferation in luminal myometrium. Cd, in the absence of hormone stimulation, causes a slight cell hypertrophy in circular myometrium. Conclusions: Acute exposure to Cd affects differently various responses to E in the different uterine cell-types. Future studies should verify whether this effect explains Cd-induced infertility, postpubertal sex organ development and whether prenatal or early postnatal exposure to Cd induces delayed persistent effects.

Effect of chronic exposure to lead on estrogen action in the prepubertal rat uterus.

Lead is a widely spread environmental pollutant known to affect both male and female reproductive systems in humans and in experimental animals. The present study investigated the effect of a chronic exposure to lead on different parameters of estrogen stimulation in the uteri of prepubertal rats. Chronic exposure to lead enhanced some parameters of estrogen stimulation, inhibited other estrogenic responses, while the remainder were unaltered. Estrogen-induced uterine eosinophilia (24 h), the proportion of uterine eosinophils in the mesometrium (6 h), and luminal epithelial hypertrophy and RNA content (24 h) appeared to be enhanced by lead exposure, compared to lead-unexposed control animals. Eosinophilia in the endometrium (6 h), the proportion of uterine eosinophils in the endometrium (6 and 24 h), edema in superficial and deep endometria (6 h), luminal epithelial hypertrophy (6 h), and mitotic response (cell proliferation) in all uterine cell types were inhibited by lead exposure, whereas circular myometrial hypertrophy was not significantly modified. The effects of lead exposure on responses to estrogen found in this study showed some differences with those previously reported for acute or subacute exposure to lead. The results revealed an interaction with the different mechanisms of estrogen action in the uterus at various levels, suggesting that some uterine cell types are more sensitive to lead than others. The relevance of the results for lead-induced infertility is discussed in this article, and possible mechanisms of action are proposed.

Antiestrogenic activity of lead

Lead is a widely spread environmental pollutant known to affect both male and female reproductive systems in humans and experimental animals. The present study investigated the effect of an acute exposure to lead (75 μg lead per gram of body weight) 1 or 24 h before hormone treatment on different parameters of estrogen stimulation in the rat uterus. Lead pretreatment enhanced some parameters of estrogen stimulation and inhibited other estrogenic responses, and the remaining parameters were unaltered. The interaction with responses to estrogen was different depending on whether lead pretreatment was 1 or 24 h before hormone stimulation. The estrogenic responses mostly affected were uterine eosinophilia, endometrial edema, uterine luminal epithelial hypertrophy, and mitosis in various—but not all—uterine cell types. In some cell types, estrogen-induced mitotic response developed earlier under the effect of lead exposure. Results revealed an interaction with the different mechanisms of estrogen action in the uterus at various levels, that some cell types are more sensitive to lead than others, and that the effect of exposure changed with time after lead pretreatment. The relevance of the results are discussed in relation to lead-induced infertility, mutagenicity, and carcinogenicity; possible mechanisms of action are proposed. © 1998 John Wiley & Sons, Inc. Environ Toxicol Water Qual 13: 43–53, 1998

Short-term inhalation toxicity of methanol, gasoline, and methanol/gasoline in the rat.

Four- to five-week-old male and female Sprague Dawley rats were exposed to vapors of methanol (2500 ppm), gasoline (3200 ppm), and methanol/gasoline (2500/3200 ppm, 570/3200 ppm) six hours per day, five days per week for four weeks. Control animals were exposed to filtered room air only. Depression in body weight gain and reduced food consumption were observed in male rats, and increased relative liver weight was detected in rats of both sexes exposed to gasoline or methanol/gasoline mixtures. Rats of both sexes exposed to methanol/gasoline mixtures had increased relative kidney weight and females exposed to gasoline and methanol/gasoline mixtures had increased kidney weight. Decreased serum glucose and cholesterol were detected in male rats exposed to gasoline and methanol/gasoline mixtures. Decreased hemoglobin was observed in females inhaling vapors of gasoline and methanol/gasoline at 570/3200 ppm. Urine from rats inhaling gasoline or methanol/gasoline mixtures had up to a fourfold increase in hippuric acid, a biomarker of exposure to the toluene constituent of gasoline, and up to a sixfold elevation in ascorbic acid, a noninvasive biomarker of hepatic response. Hepatic mixed-function oxidase (aniline hydroxylase, aminopyrine N-demethylase and ethoxyresorufin O-deethylase) activities and UDP-glucuronosyltransferase activity were elevated in rats exposed to gasoline and methanol/gasoline mixtures. Histopathological changes were confined to very mild changes in the nasal passages and in the uterus, where decreased incidence or absence of mucosal and myometrial eosinophilia was observed in females inhaling gasoline and methanol/gasoline at 570/3200 ppm. It was concluded that gasoline was largely responsible for the adverse effects, the most significant of which included depression in weight gain in the males, increased liver weight and hepatic microsomal enzyme activities in both sexes, and suppression of uterine eosinophilia. No apparent interactive effects between methanol and gasoline were observed.

Effects of Estrogen Administration on Eosinophil Infiltration into the Uterus of Mast Cell Deficient (W/W<SUP>v</SUP>) Mice

The effect of estrogen administration on eosinophil infiltration into the uterus was examined. To investigate the role of mast cells in eosinophil infiltration, genetically mast cell-deficient (W/Wv) mice were used. The ovariectomized W/Wv mice were injected subcutaneously with 7 doses (0.001-0.25μg/g BW) of estradiol-17β (E2) once a day for 2 days. The treatment resulted in significant increases in the uter-ine weight and the number of uterine eosinophils compared to the vehicle-injected control W/Wv mice 24 hrs after the second injection. Although the increases were dependent on the dose of E2 administered, the magnitude of the responses was maximal in the uterus treated with the doses over 0.05μg/g BW. Fur-thermore the uterine weight in the treated mice was not increased between 24 and 48 hrs after the second injection of E2 (0.15 μg/g BW). On the other hand, the number of eosinophils was increased until 48 hrs after the injection. The E2 treatment at a dose of 0.15 μg/g BW resulted in a significant increase in histamine content of the uterus than that of the vehicle-injected control. However, there was no difference in the con-centration of the uterine histamine between the treated and control groups. These data suggest that the E2 induced uterine eosinophilia is not mediated by mast cells in the W/Wv mice.

Prenatal androgenization selectively modifies some responses to oestrogen in the prepubertal rat uterus.

Exposure of fetuses to some hormonally active agents may imprint permanent changes on the action of related hormones. These changes can be detected in adulthood as a modification of the degree of responsiveness to hormone action. The present study describes the effect of prenatal androgenization on the various responses to oestrogen in different types of cells in the uterus of prepubertal rats. Prenatal androgenization completely abolishes oestrogen-induced hypertrophy of uterine luminal and glandular epithelium, while it does not interfere with hypertrophy of circular myometrium and potentiates uterine eosinophilia and oedema. This dissociation between the various responses to oestrogen suggests that prenatal androgenization does not equally affect all uterine cell types.

The estrogenic responses to clomiphene in the different cell types of the rat uterus: morphometrical evaluation.

The present study was designed to investigate the dose-response of clomiphene on several estrogenic responses in the immature rat uterus and to compare it to available data on estradiol-17 beta. A dissociation was demonstrated among the different estrogenic responses induced by clomiphene. Very high doses of clomiphene were needed to induce the 6-h uterine eosinophilia and deep endometrial edema, and maximal response levels were not reached at any dose studied. On the contrary, many genomic responses were induced with much lower doses of clomiphene, and maximal response levels were reached with at least the two highest doses of clomiphene. This dissociation is in agreement with the existence of separate groups of responses that are mediated by multiple and independent mechanisms of estrogen action involving different kind of receptors. Luminal epithelial, glandular epithelial, and myometrial hypertrophies were also found to differ with regard to the dose needed to induce this response in each cell type. The dissociation between genomic responses of the different uterine cell types supports the hypothesis of different estrogen receptors for each kind of cell. Clomiphene induces mitoses in the different cell types, but the proportion of mitoses in the cell types was different from that described for estradiol. It is suggested that these differences are also due to differences between receptors involved in cell proliferation.

Colloidal carbon blocks oestrogen-induced migration of eosinophils to the uterus and the uterine water imbibition response.

Oestrogen induces a migration of eosinophil leukocytes to the uterus where, it is suggested, these cells mediate several responses to hormone stimulation. To investigate the mechanism of the recognition of the uterus by the eosinophils, the present study describes the effect of a blockade of the rat reticulo-endothelial system with colloidal carbon on oestrogen-induced uterine eosinophilia, and other responses to oestrogen stimulation that, it has been suggested, are mediated by eosinophils. In the absence of oestrogen colloidal carbon induced an increase in the number of eosinophils in mesometrium but not in endometrium with myometrium, and a slight oedematous reaction in deep endometrium. Colloidal carbon abolished the oestrogen-induced increase in the number of eosinophils in endometrium with myometrium and drastically decreased the oestrogen-induced increase in uterine wet weight and the endometrial oedematous responses 6 h after the administration of oestrogen. The present results agree with the hypothesis that most uterine water imbibition is mediated by eosinophils and suggest a possible mechanism for the interaction of colloidal carbon with eosinophil migration to the uterus.

Effects of various doses of catecholestrogens on uterine eosinophilia in the immature rat

Effects of various doses of catecholestrogens on uterine eosinophilia in the immature rat

Effect of various doses of catecholestrogens on uterine eosinophilia in the immature rat

This paper describes the induction of uterine eosinophilia as well as of deep endometrial edema and increase of uterine wet weight in the immature rat by the catecholestrogens 2-OH-estradiol and 4-OH-estradiol. These effects are thought to be mediated by eosinophils via a specific eosinophil receptor system. 4-OH-estradiol was equipotent with estradiol, whereas the effect of 2-OH-estradiol was significantly weaker.

Estrogen-induced increase in eosinophil number and peroxidase activity in uterus of genetically mast cell-deficient W/Wv mice.

The role of mast cells in induction of uterine eosinophilia was investigated by using genetically mast cell-deficient (WB X C57BL/6)F1-W/Wv (hereafter called WBB6F1-W/Wv) mice. The injection of estradiol-17 beta (0.16 micrograms/g body weight) increased the peroxidase activity and eosinophil number in the uteri of castrated WBB6F1-W/Wv and WBB6F1-+/+ mice. Since no significant differences were detectable between these two type of mice, mast cells did not seem to be essential for the estrogen-induced uterine eosinophilia, at least in mice.

Dissociation of uterine eosinophilia and water imbibition from other estrogen-induced responses by nafoxidine pretreatment

We investigated the effect of pretreatment of immature rats with 5 or 50 μg nafoxidine (UA), or with 0.05 μg 17 β-estradiol (E 2) on several uterine responses elicited by treatment with a test injection of 15 μg E 2, administered 48 h after pretreatment. Early (6 h) and late (24 h) responses were measured, including wet weight, RNA, protein and glycogen content and number of blood eosinophils per uterus. The results showed that, like a 24 h pretreatment with 5 μg UA, a 48 h pretreatment with either of the UA doses dissociated the early wet weight response from the late responses to E 2 treatment, only the former being restored. In the case of E 2 pretreatment, both types of response to E 2 treatment were reinstalled. By contrast, uterine eosinophilia, induced 6 and 24 h after E 2 treatment, was not only restored but even markedly amplified following any of the 3 pretreatments. This was obtained without amplification of the early wet weight response and with various levels of the other parameters at the time of administration of the test E 2 injection (i.e. due to the pretreatment alone). From this it may be concluded that if the previously documented correlation between estrogen-induced eosinophilia and edema actually reflects the existence of a causal link between the 2 responses, as postulated by Tchernitchin in 1972, this would be with eosinophils controlling edema, rather than the reverse. Testable working hypotheses for the mechanism of amplification of the eosinophil response are proposed.

Effect of theophylline on nuclear retention of oestrogenreceptor complexes: correlation with oestrogen responses.

In the ovariectomized adult rat uterine oedema induced by 0.01 and 0.1 micrograms oestradiol-17 beta/100g body weight increased further in the presence of theophylline. Nuclear retention of oestrogen-receptor complexes also increased in response to theophylline both in vivo and in vitro. Theophylline decreased the number of eosinophils in the blood and concurrently decreased oestrogen-induced uterine eosinophilia at doses of 0.001, 0.01, 0.1, 1, 10 or 30 micrograms oestradiol/100 g body weight, through a mechanism independent of glucocorticoids. There was, therefore, no correlation between changes in the number of uterine eosinophils and changes in uterine wet weight induced by theophylline and oestrogen. It is suggested that the presence of oestrogen-receptor complexes in the nucleus for at least 4 h is a prerequisite for the induction of uterine oedema and growth in the presence of theophylline and oestradiol-17 beta.

Inhibition of non-genomic responses to oestrogen in the rat uterus by testosterone propionate.

Testosterone propionate (50 mg/kg), administered together with oestradiol, inhibited the oestrogen-induced uterine eosinophilia, deep endometrial oedema and the increase in uterine wet weight, 6 h after treatment. The same dose of the androgen decreased the number of eosinophils in the blood and increased their degranulation, explaining the effect of testosterone in the uterus. The high doses of the androgen used were in the range of the doses reported by others to block selectively the oestrogen-induced increase in uterine peroxidase content but not other responses to oestrogen or the cytosolic oestrogen receptor translocation to the nucleus. The dissociation by high doses of testosterone of the oestrogen-induced uterine eosinophilia, wet weight increase and oedema from other responses to oestrogen in the absence of any measurable effect of testosterone upon cytosolic-nuclear oestrogen receptors supports the idea that uterine eosinophilia and oedema are oestrogenic responses regulated by mechanisms different from those of the genomic responses, and is in agreement with the hypothesis of the mediation of uterine oedema by eosinophils.

Progesterone interaction with eosinophils and with responses already induced by oestrogen in the uterus

Progesterone pretreatment decreases oestrogen-induced uterine eosinophilia and other non-genomic responses that are possibly mediated by eosinophils. To investigate the mechanisms of this interaction, the present study describes the effects of progesterone on oestrogenic responses already induced by oestrogen treatment and the in-vivo and in-vitro effects of progesterone on blood eosinophils. Progesterone treatment of oestrogen-pretreated animals potentiated uterine eosinophilia 24 h after progesterone treatment but decreased it at later times and increased eosinophil degranulation in vivo. In addition, progesterone degranulated blood eosinophils in vitro. These findings demonstrate interaction of progesterone with oestrogenic responses mediated by eosinophils. Progesterone interaction with other oestrogenic responses was analysed for comparison; evidence is shown suggesting a role of eosinophils in oestrogen-induced uterine luminal fluid accumulation.

Eosinophil-mediated non-genomic parameters of estrogen stimulation—A separate group of responses mediated by an independent mechanism

The present report describes evidence suggesting that eosinophil leukocytes mediate a separate group of responses to estrogens (uterine edema, increase in vascular permeability, release of histamine etc.) independently from genomic activation. Conditions suppressing genomic activation do not interfere with this group of responses. Conditions interfering with eosinophil leukocyte migration to the uterus (young age blood eosinopenia, eosinopenic hormones, agents blocking cell mobility) selectively interfere with this group of responses. It was proposed that estrogen cytosol-nuclear receptors are involved in estrogen-induced genomic activation, and that estrogen receptors from eosinophil leukocytes are involved in the migration of these cells to the uterus, where they would mediate the above responses. Conditions increasing (theophylline) or decreasing (thyroid hormones, insulin) estrogen binding by eosinophils selectively modify estrogen-induced uterine eosinophilia and the responses to estrogen proposed to be mediated by eosinophils in the uterus. A mechanism is proposed explaining estrogen effects mediated by eosinophils.

Multiple mechanisms of regulation of estrogen action in the rat uterus: effects of insulin.

Eosinophils appear in the rat uterus in the presence of estrogen. The level of these cells in the uterus depends on the number of blood eosinophils. Insulin is an eosinopenic hormone in the blood and, therefore, could regulate estrogenic responses mediated by these cells in the uterus. Estrogen-induced uterine edema and eosinophilia at doses of 0.01,. 0.1, 1, 10, and 30 micrograms 17 beta-estradiol (E2)/100 g BW are inhibited by insulin. Estrogen binding by uterine eosinophils in vitro decreases in the presence of insulin, suggesting another explanation for the observations in the uterus in vivo. Injection of insulin alone or in combination with 0.01, 0.01, 0.1, or 1 microgram E2/100 g BW increases uterine RNA and protein contents by 6 h. Inactive insulin does not modify any of these stimulatory effects of estrogen. The results support the idea of two separate receptor systems for estrogens in the rat uterus: the eosinophil receptor system, which mediates estrogen-induced uterine edema, and the cytosol-nuclear receptor system, which mediates estrogen-induced uterine RNA and protein syntheses.