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PloS One 2014Felids generally follow a poly-estrous reproductive strategy. Eurasian lynx (Lynx lynx) display a different pattern of reproductive cyclicity where physiologically...
Felids generally follow a poly-estrous reproductive strategy. Eurasian lynx (Lynx lynx) display a different pattern of reproductive cyclicity where physiologically persistent corpora lutea (CLs) induce a mono-estrous condition which results in highly seasonal reproduction. The present study was based around a sono-morphological and endocrine study of captive Eurasian lynx, and a control-study on free-ranging lynx. We verified that CLs persist after pregnancy and pseudo-pregnancy for at least a two-year period. We could show that lynx are able to enter estrus in the following year, while CLs from the previous years persisted in structure and only temporarily reduced their function for the period of estrus onset or birth, which is unique among felids. The almost constant luteal progesterone secretion (average of 5 ng/ml serum) seems to prevent folliculogenesis outside the breeding season and has converted a poly-estrous general felid cycle into a mono-estrous cycle specific for lynx. The hormonal regulation mechanism which causes lynx to have the longest CL lifespan amongst mammals remains unclear. The described non-felid like ovarian physiology appears to be a remarkably non-plastic system. The lynx's reproductive ability to adapt to environmental and anthropogenic changes needs further investigation.
Topics: Animals; Corpus Luteum; Corpus Luteum Maintenance; Estrogens; Estrus; Female; Longitudinal Studies; Lynx; Pregnancy; Prostaglandins; Reproducibility of Results; Seasons; Ultrasonography
PubMed: 24599348
DOI: 10.1371/journal.pone.0090469 -
Biology of Reproduction Feb 2014The in vivo chronic and in vitro acute effects of di(2-ethylhexyl) phthalate (DEHP) on the reproductive function of peroxisome proliferator-activated receptor gamma...
In vivo chronic and in vitro acute effects of di(2-ethylhexyl) phthalate on pseudopregnant rabbit corpora lutea: possible involvement of peroxisome proliferator-activated receptor gamma.
The in vivo chronic and in vitro acute effects of di(2-ethylhexyl) phthalate (DEHP) on the reproductive function of peroxisome proliferator-activated receptor gamma (PPARG) were studied in rabbit corpora lutea (CL) at early stage (Day 4), midstage (Day 9), and late stage (Day 13) of pseudopregnancy. The rabbits were in vivo treated with DEHP for 15 days before induction of pseudopregnancy. Immunohistochemistry provided evidence for the presence of PPARG, prostaglandin endoperoxide synthase 1 (PTGS1), PTGS2, prostaglandin E2-9-ketoreductase (PGE2-9-K), and 3beta-hydroxysteroid dehydrogenase (3beta-HSD) in all the luteal cells during pseudopregnancy. DEHP decreased progesterone plasma levels and CL production in all the luteal stages and PPARG protein and gene expressions in early and mid-CL. DEHP in vivo treatment reduced PTGS2 protein expression at the late stage and that of PGE2-9-K at all the stages, whereas PTGS1 and 3beta-HSD were not affected. In in vitro cultured CL, DEHP alone, the PPARG antagonist T0070907 alone, or DEHP plus T0070907 diminished progesterone production and 3beta-HSD activity and increased PGF2alpha and PTGS2 in early and mid-CL, whereas DEHP plus the PPARG agonist 15d-PGJ2 did not affect these hormones and enzymes. All the in vitro treatments did not affect PGE2 secretion as well as PTGS1 and PGE2-9-K enzymatic activities in all the luteal stages. These results provided evidence that DEHP favors functional luteolysis of pseudopregnant rabbit CL, with a mechanism that seems to involve PPARG expression down-regulation, an increase of PTGS2 activity and prostaglandin F2alpha secretion, 3beta-HSD down-regulation, and decrease in progesterone.
Topics: Animals; Cells, Cultured; Corpus Luteum; Cyclooxygenase 2; Diethylhexyl Phthalate; Environmental Pollutants; Female; Ovulation; PPAR gamma; Plasticizers; Pseudopregnancy; Rabbits; Time Factors; Toxicity Tests, Acute; Toxicity Tests, Chronic
PubMed: 24403546
DOI: 10.1095/biolreprod.113.109223 -
Reproductive Medicine and Biology Jul 2014The present study aims to investigate the effects of nicotine on the endometrial decidual growth and levels of estrogen and progesterone in pseudopregnant rats.
PURPOSE
The present study aims to investigate the effects of nicotine on the endometrial decidual growth and levels of estrogen and progesterone in pseudopregnant rats.
METHODS
Pseudopregnancy (pc) was induced in cyclic Sprague-Dawley rats by sterile mating. Subcutaneous injection of nicotine tartrate (7.5 mg/kg/day) was scheduled from day 1 through day 5, day 5 through day 9 or day 1 through day 9 of pc. In another group of pseudopregnant rats, concomitant treatment of nicotine tartrate concurrently with progesterone (2 mg/day) was scheduled from day 1 through day 9 pc. Control groups received subcutaneous injections of vehicle only. Endometrial decidualization was induced on day 5 pc. On day 10 pc, animals were sacrificed.The degree of decidual growth and circulating levels of estrogen and progesterone were measured.
RESULTS
The decidual growth in all the first three nicotine-treated groups of animals was significantly reduced, particularly in the animals treated with nicotine from day 1 through day 9 pc. Plasma estrogen levels were significantly elevated in animals treated with nicotine from day 1 through day 9 pc. Conversely, levels of plasma progesterone were found to be significantly attenuated in the same group of nicotine-treated animals compared to controls. Exogenous replacement of progesterone, however, caused a higher degree of endometrial decidualization compared to the nicotine-treated group but it was slightly less than when compared to control.
CONCLUSIONS
In conclusion, nicotine-induced progesterone deficiency with a corresponding elevation of estrogen may possibly attenuate the degree of endometrial decidualization in pseudopregnant rats.
PubMed: 29699157
DOI: 10.1007/s12522-013-0174-9 -
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 -
Reproductive Sciences (Thousand Oaks,... Jun 2014Embryo implantation is a complex process requiring reciprocal interactions between implantation-competent blastocysts and receptive uteri. Accumulating literatures have...
Embryo implantation is a complex process requiring reciprocal interactions between implantation-competent blastocysts and receptive uteri. Accumulating literatures have indicated that T cells are involved in this process. The first signal mediated by T-cell receptor/CD3 complex and the second signal delivered by costimulatory molecules are essential for the differentiation of T cell into an effector cell. Expression and function of CD28, an important costimulatory molecule, during early pregnancy in mice is still unclear. In the present study, we investigated the expression pattern of CD28 in mouse uterus during early pregnancy and pseudopregnancy by real-time quantitative polymerase chain reaction, Western blotting, in situ hybridization, and immunohistochemistry (IHC). We found that injection of the uterine horn with CD28 antisense oligodeoxynucleotides leads to a decreased number of implantation sites. The expression pattern of CD3 protein examined by IHC is similar to that of CD28. These findings suggest that CD28 participates in the process of embryo implantation in mice, which might play its role through delivering the second costimulatory signal.
Topics: Animals; CD28 Antigens; Embryo Implantation; Female; Male; Mice; Pregnancy; Uterus
PubMed: 24336670
DOI: 10.1177/1933719113512537 -
Reproductive Biology and Endocrinology... Dec 2013CREBZF is a member of the mammalian ATF/CREB family of the basic region-leucine zipper (bZIP) transcription factors. Two isoforms of CREBZF have been identified from the...
BACKGROUND
CREBZF is a member of the mammalian ATF/CREB family of the basic region-leucine zipper (bZIP) transcription factors. Two isoforms of CREBZF have been identified from the alternative usage of initiation codons, SMILE (long isoform of CREBZF) and Zhangfei (short isoform of CREBZF). Until recently, the physiological function of CREBZF in mammalian reproductions has not been reported.
METHODS
Multiple techniques were performed to investigate the spatiotemporal expression and hormonal regulation of the CREBZF gene in the mouse uterus and its role in embryo implantation.
RESULTS
Zhangfei was not detected in the mouse uterus. SMILE immunostaining was mainly expressed in the uterine luminal and glandular epithelium, and the expression levels of both SMILE mRNA and protein gradually decreased from days 1-3 of pregnancy, peaked on day 4, and then declined again on day 6. On day 5 of pregnancy, SMILE protein expression was detected only in the luminal epithelium at implantation sites compared with the expression at inter-implantation sites. SMILE protein was not detected in decidual cells from days 6-8 of pregnancy or artificial decidualisation. Furthermore, SMILE protein was not detected in the mouse uterus on days 3-6 of pseudopregnancy, and SMILE expression was also induced in the delayed-implantation uterus, indicating that the presence of an active blastocyst was required for SMILE expression at the implantation site. Oestrogen significantly stimulated SMILE expression in the ovariectomised mouse uterus. In addition, in cycling mice, high levels of SMILE protein and mRNA expression were also observed in proestrus and oestrus uteri.
CONCLUSIONS
Taken together, these results suggested that SMILE expression was closely related to mouse implantation and up-regulated by oestrogen.
Topics: Animals; Basic-Leucine Zipper Transcription Factors; Embryo Implantation; Estrogens; Female; Gene Expression Regulation, Developmental; Mice; Pregnancy; Pregnancy, Animal; Protein Isoforms; RNA, Messenger; Uterus
PubMed: 24325733
DOI: 10.1186/1477-7827-11-110 -
Biochemical and Biophysical Research... Nov 2013Progesterone (P4) and progesterone receptor (PR) have important functions in uterine environment. In previous studies, using high density DNA microarray analysis, we...
Progesterone (P4) and progesterone receptor (PR) have important functions in uterine environment. In previous studies, using high density DNA microarray analysis, we identified low density lipoprotein receptor-related protein 2 (Lrp2) is one of the genes upregulated by P4 and PR. In present studies, we examined the expression of Lrp2 through real-time PCR, in situ hybridization and immunohistochemistry by P4-PR response. Lrp2 mRNA transcript was significantly increased after P4 treatment in the luminal and glandular epithelium of the wild-type mice. However, Lrp2 expression was not observed in the progesterone receptor knock out (PRKO) mice treated with P4. The expression of Lrp2 expression is not regulated by estrogen. During early pregnancy, the expression of Lrp2 was detected at 2.5 dpc and then significantly increased at 3.5 dpc in luminal and glandular epithelium. These results suggest that Lrp2 is a novel target gene by P4 and PR.
Topics: Animals; Estradiol; Female; Gene Expression Regulation; Low Density Lipoprotein Receptor-Related Protein-2; Mice; Mice, Inbred C57BL; Mice, Knockout; Pregnancy; Progesterone; Pseudopregnancy; Uterus
PubMed: 24140060
DOI: 10.1016/j.bbrc.2013.10.037 -
Biology of Reproduction Oct 2013All mammalian uteri have luminal (LE) and glandular epithelia (GE) in their endometrium. The LE mediates uterine receptivity and blastocyst attachment for implantation,... (Comparative Study)
Comparative Study
All mammalian uteri have luminal (LE) and glandular epithelia (GE) in their endometrium. The LE mediates uterine receptivity and blastocyst attachment for implantation, and the GE synthesize and secrete or transport bioactive substances involved in blastocyst implantation, uterine receptivity, and stromal cell decidualization. However, the mechanisms governing uterine epithelial development after birth and their function in the adult are not fully understood. Here, comprehensive microarray analysis was conducted on LE and GE isolated by laser capture microdissection from uteri on Postnatal Day 10 (PD 10) and day of pseudopregnancy (DOPP) 2.5 and 3.5. This data was integrated with analysis of uteri from gland-containing control and aglandular progesterone-induced uterine gland knockout mice from PD 10 and DOPP 3.5. Many genes were expressed in both epithelia, but there was greater expression of genes in the LE than in the GE. In the neonate, GE-expressed genes were enriched for morphogenesis, development, migration, and retinoic acid signaling. In the adult, LE-expressed genes were enriched for metabolic processes and steroid biosynthesis, whereas retinoid signaling, tight junction, extracellular matrix, and regulation of kinase activity were enriched in the GE. The transcriptome differences in the epithelia support the idea that each cell type has a distinct and complementary function in the uterus. The candidate genes and regulatory networks identified here provide a framework to discover new mechanisms regulating development of epithelia in the postnatal uterus and their functions in early pregnancy.
Topics: Aging; Animals; Animals, Newborn; Decidua; Endometrium; Female; Fertility Agents, Female; Gene Expression Profiling; Gene Expression Regulation, Developmental; Gene Knockout Techniques; Laser Capture Microdissection; Mice; Mice, Inbred C57BL; Mice, Inbred Strains; Oligonucleotide Array Sequence Analysis; Progesterone; Pseudopregnancy; Transcription, Genetic; Transcriptome; Uterus
PubMed: 23946541
DOI: 10.1095/biolreprod.113.111971 -
Cell Reports Jun 2013Embryonic stem cells (ESCs) are derived from mammalian embryos during the transition from totipotency, when individual blastomeres can make all lineages, to...
Embryonic stem cells (ESCs) are derived from mammalian embryos during the transition from totipotency, when individual blastomeres can make all lineages, to pluripotency, when they are competent to make only embryonic lineages. ESCs maintained with inhibitors of MEK and GSK3 (2i) are thought to represent an embryonically restricted ground state. However, we observed heterogeneous expression of the extraembryonic endoderm marker Hex in 2i-cultured embryos, suggesting that 2i blocked development prior to epiblast commitment. Similarly, 2i ESC cultures were heterogeneous and contained a Hex-positive fraction primed to differentiate into trophoblast and extraembryonic endoderm. Single Hex-positive ESCs coexpressed epiblast and extraembryonic genes and contributed to all lineages in chimeras. The cytokine LIF, necessary for ESC self-renewal, supported the expansion of this population but did not directly support Nanog-positive epiblast-like ESCs. Thus, 2i and LIF support a totipotent state comparable to early embryonic cells that coexpress embryonic and extraembryonic determinants.
Topics: Animals; Cell Differentiation; Cells, Cultured; Embryonic Stem Cells; Female; Humans; Mice; Mice, Inbred C57BL; Mice, Transgenic; Pseudopregnancy; Totipotent Stem Cells
PubMed: 23746443
DOI: 10.1016/j.celrep.2013.04.034 -
Reproductive Biology and Endocrinology... May 2013This literature review on pseudocyesis or false pregnancy aims to find epidemiological, psychiatric/psychologic, gynecological and endocrine traits associated with this... (Review)
Review
This literature review on pseudocyesis or false pregnancy aims to find epidemiological, psychiatric/psychologic, gynecological and endocrine traits associated with this condition in order to propose neuroendocrine/endocrine mechanisms leading to the emergence of pseudocyetic traits. Ten women from 5 selected studies were analyzed after applying stringent criteria to discriminate between cases of true pseudocyesis (pseudocyesis vera) versus delusional, simulated or erroneous pseudocyesis. The analysis of the reviewed studies evidenced that pseudocyesis shares many endocrine traits with both polycystic ovarian syndrome and major depressive disorder, although the endocrine traits are more akin to polycystic ovarian syndrome than to major depressive disorder. Data support the notion that pseudocyetic women may have increased sympathetic nervous system activity, dysfunction of central nervous system catecholaminergic pathways and decreased steroid feedback inhibition of gonadotropin-releasing hormone. Although other neuroendocrine/endocrine pathways may be involved, the neuroendocrine/endocrine mechanisms proposed in this review may lead to the development of pseudocyetic traits including hypomenorrhea or amenorrhea, galactorrhea, diurnal and/or nocturnal hyperprolactinemia, abdominal distension and apparent fetal movements and labor pains at the expected date of delivery.
Topics: Depressive Disorder, Major; Diagnosis, Differential; Female; Gonadotropin-Releasing Hormone; Humans; Nervous System Physiological Phenomena; Polycystic Ovary Syndrome; Pseudopregnancy
PubMed: 23672289
DOI: 10.1186/1477-7827-11-39