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The Journal of Reproduction and... Feb 2010Mammalian embryonic implantation requires reciprocal interactions between implantation-competent blastocysts and a receptive uterus. Some microRNAs might play a key role...
Mammalian embryonic implantation requires reciprocal interactions between implantation-competent blastocysts and a receptive uterus. Some microRNAs might play a key role during embryo implantation in the mouse, but the let-7a expression profiles in the rat uterus during peri-implantation are unknown. In the study, the expression of let-7a in the uterus during early pregnancy, pseudopregnancy, artificial decidualization and activation of delayed implantation was detected by Northern blotting and in situ hybridization. The effect of steroid hormones on let-7a expression was also detected by Northern blotting and in situ hybridization. Here, we found that the expression level of let-7a was higher on gestation day 6-7 (g.d. 6-7) in rats than on g.d.4-5 and g.d.8-9. Let-7a was specifically localized in glandular and luminal epithelia and decidua. The expression of let-7a was not significantly different in the pseudopregnant uterus and increased significantly in the uteri of rats subjected to artificial decidualization and activation of delayed implantation. Treatment with estradiol-17beta or progesterone significantly increased let-7a expression. Thus, let-7a expression was significantly induced by the process of embryo invasion, and this increased expression level was mainly induced by active blastocysts and decidualization during the window of implantation, implying that let-7a may participate in endometrial decidualization. Steroid hormones, estradiol-17beta or progesterone stimulated let-7a expression.
Topics: Animals; Blastocyst; Decidua; Embryo Implantation; Endometrium; Female; Gonadal Steroid Hormones; MicroRNAs; Pregnancy; Pseudopregnancy; Rats; Rats, Sprague-Dawley; Uterus
PubMed: 19881221
DOI: 10.1262/jrd.09-088k -
Animal Reproduction Science Feb 2010Coyotes (Canis latrans) are seasonally monestrous and form perennial pair-bonds. Breeding is dominated by each pack's alpha male and female, and both sexes share... (Randomized Controlled Trial)
Randomized Controlled Trial
Coyotes (Canis latrans) are seasonally monestrous and form perennial pair-bonds. Breeding is dominated by each pack's alpha male and female, and both sexes share responsibility for territory defense and pup-rearing. They are also opportunistic predators on domestic livestock and pets. But while dominant adults have been implicated as primary killers, depredation is reduced when coyotes are without pups. Contraception, therefore, may represent a non-lethal solution for conflicts between coyotes and humans. Steroid hormones successfully control fertility in some species, but have been considered contraindicated in wildlife and canids in particular; specific concerns include possible induction of aberrant behavior, or uterine and hematopoietic pathologies. Herein we describe a study examining the physiological effectiveness, health safety, and behavioral consequences following treatment of estrous coyotes with exogenous estrogen. We treated captive adult female coyotes in estrus with 0.01mg/kg estradiol benzoate (EB), either before (n=5) or immediately after ovulation (n=6), then documented reproductive outcome, physiological variables and behavioral responses, during and after treatment. Pregnancy was averted in six females treated after ovulation, suggesting that appropriate timing of treatment proved crucial. A transient suppression of sexual behavior was observed, and in some cases, estrus appeared slightly lengthened. However, neither ovulation nor mating behavior was fully suppressed. Importantly, non-pregnant females (and their mates) displayed diestrous socio-sexual behavior similar to pregnant coyotes (behavioral pseudopregnancy). Furthermore, non-pregnant coyotes did not mate again until the next native breeding season, and we observed no deleterious physiological effects during diestrus or subsequent ovarian cycles.
Topics: Animals; Coyotes; Estradiol; Female; Injections, Subcutaneous; Male; Ovulation; Pregnancy; Reproduction; Seasons; Sexual Behavior, Animal
PubMed: 19523776
DOI: 10.1016/j.anireprosci.2009.05.008 -
The Journal of Veterinary Medical... Jan 2017Though Fas/Fas ligand (FasL) system-dependent apoptosis is considered to be the primary form of cell death in regressing corpus luteum (CL), the cellular identity and...
Though Fas/Fas ligand (FasL) system-dependent apoptosis is considered to be the primary form of cell death in regressing corpus luteum (CL), the cellular identity and regulation of expression of the ligand and receptor molecules are not fully understood. Here, we focused on immunohistochemical determination of Fas expression during natural regression with comparison of three different types of rat CLs. Detected Fas was in good spatial association with cleaved caspase-3 and FasL proteins and with macrophages and neutrophils. In CLs of the cycle and pseudopregnancy, Fas-positive cell types included large and small luteal (steroidogenic) cells and capillary endothelial cells mainly, and blood-derived immune cells occasionally. Fas signals were abundant at multiple focal inflammatory-like sites. In contrast, Fas signals in CL of pregnancy did not localize in steroidogenic cells, but almost exclusively in endothelial cells and granulocytes. The signals scattered evenly throughout the CL tissue as phagocytes also did. In all CLs types, the numbers of Fas-expressing cells increased transiently after functional inactivation and at the early phase of structural regression. This observation revealed spatio-temporally regulated expression of Fas that was highly associated with apoptotic and phagocytotic systems and type-dependent differences in Fas expression and phagocytes dynamics in naturally regressing CL of rats.
Topics: Animals; Caspase 3; Corpus Luteum; Fas Ligand Protein; Female; Gene Expression Regulation; Luteolysis; Macrophages; Neutrophils; Phagocytes; Pregnancy; Pseudopregnancy; Rats
PubMed: 27546215
DOI: 10.1292/jvms.16-0199 -
European Journal of Biochemistry May 2000Endocannabinoids are an emerging class of lipid mediators, which mimic several effects of cannabinoids. Anandamide (arachidonoylethanolamide) is a major endocannabinoid,...
Endocannabinoids are an emerging class of lipid mediators, which mimic several effects of cannabinoids. Anandamide (arachidonoylethanolamide) is a major endocannabinoid, which has been shown to impair pregnancy and embryo development. The activity of anandamide is controlled by cellular uptake through a specific transporter and intracellular degradation by the enzyme anandamide hydrolase (fatty acid amide hydrolase, FAAH). We characterized FAAH in mouse uterus by radiochromatographic and immunochemical techniques, showing that the enzyme is confined to the epithelium and its activity decreases appreciably during pregnancy or pseudopregnancy because of lower gene expression at the translational level. Ovariectomy prevented the decrease in FAAH, and both progesterone and estrogen further reduced its basal levels, suggesting hormonal control of the enzyme. Anandamide was shown to induce programmed cell death in mouse blastocysts, through a pathway independent of type-1 cannabinoid receptor. Blastocysts, however, have a specific anandamide transporter and FAAH, which scavenge this lipid. Taken together, these results provide evidence of an interplay between endocannabinoids and sex hormones in pregnancy. These findings may also be relevant for human fertility, as epithelial cells from healthy human uterus showed FAAH activity and expression, which in adenocarcinoma cells was increased fivefold.
Topics: Adenocarcinoma; Amidohydrolases; Animals; Apoptosis; Blastocyst; Cannabinoid Receptor Modulators; Dose-Response Relationship, Drug; Down-Regulation; Epithelium; Estrogens; Female; Gonadal Steroid Hormones; Humans; Kinetics; Mice; Ovary; Pregnancy; Pregnancy, Animal; Progesterone; Pseudopregnancy; Time Factors; Tumor Cells, Cultured; Uterus
PubMed: 10806398
DOI: 10.1046/j.1432-1033.2000.01316.x -
Fertility and Sterility Jan 1976Uteroglobin was measured under various hormonal conditions: pregnancy, pseudopregnancy, pseudopregnancy with exogenous progesterone, pseudopregnancy with exogenous...
Uteroglobin was measured under various hormonal conditions: pregnancy, pseudopregnancy, pseudopregnancy with exogenous progesterone, pseudopregnancy with exogenous 20alpha-hydroxyprogesterone, ovariectomy with exogenous progesterone, ovariectomy with exogenous estrogen, ovariectomy with exogenous estrogen and progesterone, and ovariectomy with either exogenous progesterone or estrogen and progesterone, plus uterine trauma. In pregnant females, uteroglobin levels diminished sharply after day 9. In pseudopregnancy, high concentrations were maintained through day 14. Although exogenous progesterone did not prevent this decrease in pseudopregnant females, re-elevation occurred in the continued presence of progesterone. A similar pattern of decline and re-elevation was found in ovariectomized females that received injections of estrogen and progesterone. With an increase in estrogen dosage, the period of uteroglobin secretion was shorter and the magnitude lower. Ovariectomized females receiving only progesterone did not manifest a clear uteroglobin diminution. Uterine trauma on day 7 of exogenous steroid administration to ovariectomized females was followed by a diminution in uteroglobin. At the dosage level used, administration of 20alpha-hydroxyprogesterone did not affect the peak uteroglobin secretion occurring on day 5 of pseudopregnancy. Ovariectomized females receiving estrogen or sesame oil vehicle had barely detectable levels of uteroglobin. A uteroglobin-estrogen complex is suggested as a possible inhibitor of uteroglobin synthesis by a feedback inhibition pathway in pseudopregnant females and in ovariectomized females treated with progesterone plus estrogen. In pregnant females, a uteroglobin-estrogen complex and/or the uterine decidual response to implantation could control uteroglobin synthesis.
Topics: 20-alpha-Dihydroprogesterone; Animals; Castration; Estradiol; Estrogens; Female; Glycoproteins; Ovary; Pregnancy; Progesterone; Pseudopregnancy; Rabbits; Uteroglobin; Uterus
PubMed: 1245243
DOI: No ID Found -
Fertility and Sterility Aug 1975Administration of dehydroepiandrosterone (DHA) to the immature female rat resulted in one precocious ovulation followed by ovulatory failure. The animals exhibited...
Administration of dehydroepiandrosterone (DHA) to the immature female rat resulted in one precocious ovulation followed by ovulatory failure. The animals exhibited either "constant-estrus" or "constant-diestrus" vaginal smears, and the ovaries were either polycystic or contained corpus luteum-like structures. Serum follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels showed an ovulatory type surge on day 30, at the time of the precocious ovulation. Thereafter, serum FSH levels were comparable to those of control rats, whereas the LH levels were very low. Serum prolactin was elevated significantly in DHA-treated animals. The ovaries of DHA-treated animals were responsive to gonadotropins and the pituitary was responsive to luteinizing hormone-releasing hormone. Withdrawal of androgen treatment resulted in restoration of cyclicity. This animal model demonstrates that an androgen insult can cause ovulatory failure and polycystic ovaries in spite of normal ovaries, adrenals, and hypothalamic-pituitary mechanisms. That such ovulatory failure is a result of the androgen administration is further substantiated by restoration of cyclicity after androgen withdrawal. This animal model in several ways is similar to the human polycystic ovary syndrome and has a potential application in the study of the mechanism of androgen-induced ovulatory failure.
Topics: Animals; Anovulation; Chorionic Gonadotropin; Dehydroepiandrosterone; Female; Follicle Stimulating Hormone; Gonadotropins, Equine; Luteinizing Hormone; Organ Size; Ovarian Cysts; Ovary; Ovulation; Prolactin; Pseudopregnancy; Rats; Uterus
PubMed: 125663
DOI: No ID Found -
Endocrinology Mar 2011Estrogen signaling is pivotal for maintenance of female reproductive function in mammals. The physiological role of estrogen is mediated by estrogen receptors (ERs) and...
Estrogen signaling is pivotal for maintenance of female reproductive function in mammals. The physiological role of estrogen is mediated by estrogen receptors (ERs) and the steroid receptor coactivator family of transcriptional coregulators. Ablation of steroid receptor coactivator and ER coactivators in mice causes impaired female reproductive function. Recently we reported that prohibitin (PHB) can function as a corepressor for ERs in cultured cells. In this study, we demonstrate that PHB is an estrogen-regulated gene in vitro and in vivo, and its expression is induced by estrogen in the uterus, suggesting the existence of feedback regulatory loops. A conditional PHB knockout mouse model was generated by gene targeting to assess its in vivo function. Female mice with selective ablation of the PHB allele in the uterus were sterile, and their uteri were severely hypoplastic, indicating PHB is required for uterine development. Moreover, expression of ER and progesterone receptor target genes was selectively altered in response to hormone treatment. In summary, this study demonstrates that PHB is an estrogen-regulated gene and that PHB is essential for mouse uterine development and adult function and selectively required for estrogen-regulated gene expression.
Topics: Alleles; Animals; Breast Neoplasms; Cell Line, Tumor; Estrogens; Female; Gene Deletion; Gene Expression Regulation, Developmental; Gene Expression Regulation, Neoplastic; Genotype; Humans; Mice; Mutation; Prohibitins; Pseudopregnancy; RNA, Messenger; Repressor Proteins; Signal Transduction; Time Factors; Uterus
PubMed: 21209023
DOI: 10.1210/en.2010-0732 -
PloS One 2012The complex tissue remodeling process of menstruation is experienced by humans and some primates, whereas most placental mammals, including mice, go through an estrous...
The complex tissue remodeling process of menstruation is experienced by humans and some primates, whereas most placental mammals, including mice, go through an estrous cycle. How menstruation and the underlying mechanisms evolved is still unknown. Here we demonstrate that the process of menstruation is not just species-specific but also depends on factors which can be induced experimentally. In intact female mice endogenous progesterone levels were raised by the induction of pseudopregnancy. Following an intrauterine oil injection, the decidualization of the endometrium was reliably induced as a prerequisite for menstruation. The natural drop of endogenous progesterone led to spontaneous breakdown of endometrial tissue within an average of 3 days post induction of decidualization. Interestingly, morphological changes such as breakdown and repair of the endometrial layer occurred in parallel in the same uterine horn. Most importantly, endometrial breakdown was accompanied by vaginally visible (overt) bleeding and flushing out of shed tissue comparable to human menstruation. Real-time PCR data clearly showed temporal changes in the expression of multiple factors participating in inflammation, angiogenesis, tissue modulation, proliferation, and apoptosis, as has been described for human menstruating endometrium. In conclusion, human menstruation can be mimicked in terms of extravaginally visible bleeding, tissue remodeling, and gene regulation in naturally non-menstruating species such as intact female mice without the need for an exogenous hormone supply.
Topics: Animals; Decidua; Endometrium; Estrous Cycle; Estrus; Female; Gene Expression Regulation; Male; Menstruation-Inducing Agents; Mice; Mice, Inbred BALB C; Mifepristone; Progesterone; Pseudopregnancy; RNA, Messenger; Time Factors
PubMed: 22412950
DOI: 10.1371/journal.pone.0032922 -
The Journal of Cell Biology Jul 1962The ultrastructure of the uterine epithelium has been studied in estrous, ovariectomized, pregnant, and pseudopregnant rabbits. Tissue for light microscopy was fixed in...
The ultrastructure of the uterine epithelium has been studied in estrous, ovariectomized, pregnant, and pseudopregnant rabbits. Tissue for light microscopy was fixed in Bouin's solution and stained with hematoxylin and eosin, by the periodic acid-Schiff (PAS) method, and with methylene blue. Tissue for electron microscopy was fixed in 1 per cent osmium tetroxide in White's saline and embedded in Araldite. The uterine epithelium in estrus is comprised of ciliated and non-ciliated cells. After ovariectomy the epithelium becomes reduced in height and PAS-positive material disappears. Multinucleated cells are formed in the epithelium in pregnancy, pseudopregnancy, and in the non-pregnant horn in unilateral pregnancy. They degenerate during the 3rd week of pseudopregnancy and during the 4th week of pregnancy in the non-pregnant horn. The formation of multinucleated cells is believed to be under hormonal control. The uterine epithelium in contact with the blastocyst changes into a "symplasma," presumably under the influence of a local (chemical?) effect produced by the blastocyst. This change is not seen in pseudopregnancy nor in the non-pregnant horn in unilateral pregnancy. A complex infolding of the basal cell membrane of the epithelium accompanies the "symplasmic" change. The remaining uterine epithelium in pregnancy shows a well developed ergastoplasm suggesting a production of secretion materials, some of which may be available for absorption by the fetus through the yolk sac or paraplacental chorion.
Topics: Animals; Blastocyst; Cell Membrane; Electrons; Epithelium; Estrus; Female; Humans; Microscopy; Microscopy, Electron; Pregnancy; Pseudopregnancy; Rabbits; Uterus
PubMed: 14462496
DOI: 10.1083/jcb.14.1.49 -
Fertility and Sterility Mar 2014To illustrate an efficient, complete, step-by-step protocol for studying implantation in mice.
OBJECTIVE
To illustrate an efficient, complete, step-by-step protocol for studying implantation in mice.
DESIGN
Video presentation of an animal model for research in reproductive biology.
ANIMAL(S)
Mouse (Mus musculus).
INTERVENTION(S)
A nonsurgical embryo transfer system very similar to that used for human embryo transfer.
MAIN OUTCOME MEASURE(S)
The protocols with recipient and donor mice are performed in parallel in the same week. For the donor mice: the first step is ovarian stimulation, followed by ovulation induction and mating; finally, the mice are sacrificed, and the embryos are collected and cultured. For recipient mice: first estrous synchrony is induced, followed by mating with a vasectomized male, visualization of the vaginal plug, and nonsurgical transfer of the embryos. Finally (optionally), the implantation sites can be visualized on day 7.5 of development. (All animal experiments were performed with the approval of the institutional review board.)
RESULT(S)
Implantation is an essential step in human reproduction although, because of technical and ethics considerations, still relatively little is known about human implantation and early development. Conversely, mouse models are well established and can be used for preliminary experiments. However, there are various bottlenecks in the procedure for obtaining and transferring murine embryos, which makes experimentation with this model more difficult. These difficulties include pseudopregnancy, ovarian hyperstimulation, and embryo collection, culture, and transfer. We have proposed a complete, efficient method for obtaining, culturing, and transferring mouse blastocysts that can be easily applied in research. Potential applications include testing new media components that do not affect preimplantation but do affect implantation and early development. The embryo transfer method proposed here has been demonstrated to achieve embryo implantation easier and faster than, and in approximately similar rates as other traditional surgery methods.
CONCLUSION(S)
This workflow is the first set of complete step-by-step instructions available that incorporate advances such as nonsurgical mouse embryo transfer. This will facilitate research into different reproduction events such as embryo development, embryo implantation, or contraception.
Topics: Animals; Embryo Implantation; Embryo Transfer; Embryonic Development; Female; Male; Mice; Ovulation Induction
PubMed: 24355048
DOI: 10.1016/j.fertnstert.2013.11.021