Safe in the womb? Effects of air pollution to the unborn child and neonates

OBJECTIVE

In this brief review, the authors focus on the effects of gestational exposures to urban air pollution on fetal development and neonatal outcomes.

SOURCE OF DATA

In this review the authors used PubMed, Web of Science and SciELO research platforms, analyzing papers from the last 30 years.

SUMMARY OF THE FINDINGS

Epidemiological and experimental evidence agree that gestational exposure to air pollution in urban increases the risks for low birth weight, preterm birth, congenital malformation, intrauterine growth restriction, and neonatal mortality. Furthermore, exposures are associated with increased risks for preeclampsia, hypertension, gestational diabetes.

CONCLUSIONS

Therefore, it is time for greater involvement and engagement of the health sector in the discussion of public policies that may affect the quality of the environment, and that directly or indirectly impact the health of those who were not yet born.

Maternal exposure of mice to sodium p-perfluorous nonenoxybenzene sulfonate causes endocrine disruption in both dams and offspring

The toxicity of certain novel perfluoroalkyl substances (PFCs) has attracted increasing attention. However, the toxic effects of sodium p-perfluorous nonenoxybenzene sulfonate (OBS) on the endocrine system have not been elucidated. In this study, OBS was added to the drinking water during the pregnancy and lactation of the healthy female mice at dietary levels of 0.0 mg/L (CON), 0.5 mg/L (OBS-L), and 5.0 mg/L (OBS-H). OBS exposure during the pregnancy and lactation resulted in the presence of OBS residues in the placenta and fetus. We also analyzed physiological and biochemical parameters and gene expression levels in mice of the F0 and F1 generations after maternal OBS exposure. The total serum cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels were significantly increased in female mice of the F0 generation. The androgen levels in the serum and the ovarian mRNA levels of androgen receptor (AR) also tended to increase after maternal OBS exposure in the F0 generation mice. Moreover, maternal OBS exposure altered the mRNA expression of endocrine-related genes in male mice of F1 generation. Notably, the serum TC and LDL-C levels were significantly increased in 8-weeks-old male mice of the F1 generation, and the serum high-density lipoprotein cholesterol (HDL-C) levels were decreased in 24-week-old male mice of the F1 generation. These results indicated that maternal OBS exposure can interfere with endocrine homeostasis in the F0 and F1 generations. Therefore, exposure to OBS during pregnancy and lactation has the potential toxic effects on the dams and male offspring, which cannot be overlooked.

Effects of quercetin, vitamin E, and estrogen on Metabolic-Related factors in uterus and serum of ovariectomized rat models

AIMS

Estrogen (E2) deficiency has been related to uterine metabolic dysfunction, which could be accompanied by infertility in the reproductive ages. Despite having adverse effects, estrogen replacement therapy is considered the fundamental treatment strategy for this problem. The current study sought to determine the palliative effects of quercetin (Q) and vitamin E (Vit.E) on some of the uterine's metabolism-related factors in ovariectomized (OVX) rats and compare them with the effects of estrogen.

MATERIALS AND METHODS

Sixty-four rats were divided into eight groups. OVX animals were treated with Q (15 mg/kg/day), Vit.E (60 mg/kg/day), E2 (10 µg/kg/day), and Q (7.5 mg/kg/day) + Vit.E (30 mg/kg/day) for 10 weeks. Glucose and adiponectin were measured using glucose oxidase and ELISA, respectively. Furthermore, the present study investigated the alterations in the expression of AdipoR1, nesfatin1, and GluT4 genes.

RESULTS

Antioxidants suppress the weight gain of OVX animals. Also, Q, Vit.E, and E2 cause a significant decline in glucose and adiponectin levels (p-value < .05). Finally, the expression of AdipoR1, nesfatin1, and GLUT4 genes was significantly increased in treated OVX rats' uterus.

CONCLUSION

The present findings suggest that the administration of Q and Vit.E could demonstrate promising characteristics in a similar approach with estradiol and thus be considered as alternatives for estrogen replacement therapy.

Baicalin attenuates endometritis in a rabbit model induced by infection with Escherichia coli and Staphylococcus aureus via NF-κB and JNK signaling pathways

In this study, a rabbit endometritis model was developed to study cow endometritis. In addition, the protective effects of baicalin (a flavonoid) against endometritis were investigated. Clinical symptoms, differential leukocyte counting, uterine secretion smear microscopy and chemical examination, urine testing, and signs of necropsy showed abnormal changes and inflammatory responses in the uterus of rabbits. Histopathological results revealed visible inflammatory exudates and blood spots between intercellular spaces which confirmed that the rabbit endometritis model was successfully developed. Most importantly, these inflammatory signs were partially attenuated with baicalin treatment. The data revealed that the increased body temperature and leukocyte cells, pus, and the detachment of epithelial cells were alleviated with baicalin administration in a dose-dependent manner. Histopathological tissue changes such as inflammatory cells infiltrates, hyperemia, hemorrhages, and shedding of epithelial cells were partially attenuated with baicalin treatment. In addition, the mRNA expression of inflammation-related genes (iNOS, IL-1β, TNF-α, IL-10, IL-4, and IL-6) was significantly altered in RAW264.7 cells after LPS treatment. Further, the phosphorylated protein expression of JNK, p65, and IκBα were significantly reduced with LPS treatment. Intriguingly, baicalin pretreatment reversed the alteration in mRNA expression of inflammation-related genes and significantly reduced the phosphorylation of JNK, p65, and IκBα. In summary, our results suggest that baicalin has protective effects on bacterial-induced endometritis in rabbits that involve the suppression of NF-κB and JNK signaling pathways and pro-inflammatory cytokines.

The Influence of Bisphenol a on the Nitrergic Nervous Structures in the Domestic Porcine Uterus

Bisphenol A (BPA) is one of the most common environmental pollutants among endocrine disruptors. Due to its similarity to estrogen, BPA may affect estrogen receptors and show adverse effects on many internal organs. The reproductive system is particularly vulnerable to the impact of BPA, but knowledge about BPA-induced changes in the innervation of the uterus is relatively scarce. Therefore, this study aimed to investigate the influence of various doses of BPA on nitrergic nerves supplying the uterus with the double immunofluorescence method. It has been shown that even low doses of BPA caused an increase in the number of nitrergic nerves in the uterine wall and changed their neurochemical characterization. During the present study, changes in the number of nitrergic nerves simultaneously immunoreactive to substance P, vasoactive intestinal polypeptide, pituitary adenylate cyclase-activating peptide, and/or cocaine- and amphetamine-regulated transcript were found under the influence of BPA. The obtained results strongly suggest that nitrergic nerves in the uterine wall participate in adaptive and/or protective processes aimed at homeostasis maintenance in the uterine activity under the impact of BPA.

The Impact of a Diet Containing Sucrose and Systematically Repeated Starvation on the Oxidative Status of the Uterus and Ovary of Rats

The effect of a sucrose diet and repeated one-day starvation on oxidative status in the ovary and uterus is still unknown. Our analysis focused on carbohydrate-lipid metabolism parameters and the changes in red blood cells, ovary and uterus superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) activities and malonylodialdehyde (MDA) concentration in rats fed with a diet containing 16% of sucrose and subjected to systematic one-day starvation when using such a diet. It was found that a diet with 16% sucrose contributed to the increase of antioxidant enzyme activity in the blood (GPx and CAT) and uterus (SOD), without changes in MDA concentrations, which indicates an increase in reactive oxygen species (ROS) concentration in these tissues, being balanced by an increase in antioxidant enzyme activity. The introduction of a regular one-day starvation period into the diet intensified oxidative stress and led to a redox imbalance in the reproductive tissues of female rats. This was manifested by higher GPx activity, lower CAT activity and higher MDA concentration in the uterus and lower GPx and CAT activities and lower MDA concentration in the ovaries. The observed changes may be the cause of fertility disorders and possible problems with fertilised egg cell implantation into the uterine tissue.

Placental development during early pregnancy in sheep: nuclear estrogen and progesterone receptor mRNA expression in the utero-placental compartments

Sex steroid hormones are major regulators of uterine and placental growth and functions, as well as many other biological processes. To examine the mRNA expression of nuclear estrogen (ESR1 and 2) and progesterone (PGRAB and B) receptors in different compartments of the uterus and placenta, tissues were collected in experiment 1 on days 16, 20, and 28 after natural mating (NAT) and on day 10 after estrus (nonpregnant controls [NP]); and in experiment 2 on day 22 of NAT, and pregnancies established after transfer of embryos generated through mating of FSH-treated ewes (NAT-ET), in vitro fertilization (IVF), or in vitro activation (parthenotes). In experiment 1, ESR1 expression in endometrial stroma (ES), endometrial glands (EGs), and myometrial blood vessels (MBVs), ESR2 in endometrial blood vessels (EBV), PGRAB in ES, and PGRB in ES, EG, and MBV was greater in pregnant than NP ewes depending on the day of pregnancy. The day of pregnancy affected the expression of ESR1 in MBV, ESR2 in EBV and MBV, and PGRAB in ES. In experiment 2, ESR1, PGRAB, and PGRB in EG, but not in other compartments, was greater in NAT-ET than NAT, and PGRB was greater for NAT-ET than IVF. These data demonstrate that ESR and PGR expression differ in pregnant versus NP ewes in selected compartments and was affected by pregnancy stage or embryo origin in selected utero-placental compartments. Thus, sex steroid hormone mRNA expression is differentially regulated in a spatiotemporal manner in the uterus and placenta and is affected by the application of assisted reproductive technology in sheep.

In silico analysis of the Mus musculus uterine gene expression landscape during pregnancy identifies putative upstream regulators for labour

BACKGROUND

The molecular pathways involved in the transition from uterine quiescence to overt labour are mapped and form the currently established pharmacological targets for both the induction and inhibition of human labour. However, both spontaneous premature labour and functional dystocia occur and are difficult to treat adequately. The identification of upstream regulators involved in the onset and orchestration of labour pathways is essential to develop additional therapies that will contribute to the regulation of the timing of birth.

OBJECTIVES

To define uterine biological processes and their upstream activators involved in the transition from uterine quiescence to overt labour.

STUDY DESIGN

The uterus of non-pregnant and pregnant FVB M. musculus is collected at embryonic days (E) 6.5, 8.5, 10.5, 12.5, 15.5 and 17.5 and the uterine transcriptome is determined using the Illumina mouse Ref8v2 micro-array platform. K-means clustering and Ingenuity Pathway Analysis are applied to further dissect the transcriptome data.

RESULTS

From E6.5 to E17.5, 5405 genes are significantly differentially expressed and they segregate into 7 unique clusters. Five of the 7 clusters are enriched for genes involved in specific biological processes that include regulation of gene-expression, T-cell receptor activation, Toll-like receptor signalling and steroid metabolism. The identification of upstream activators for differentially expressed genes between consecutive time points highlights the E10.5 to E12.5 window during which the role from progesterone switches from an activated state to the inhibited state reflecting the process of functional progesterone withdrawal essential for the transgression from myometrial quiescence to synchronized contractions. For this time window in which 189 genes are differentially expressed we define 22 putative upstream activators of which NUPR1 and TBX2 are the most significant with respectively an activated and an inhibited status.

CONCLUSIONS

Gene expression profiling of mice uterus from E6.5 to E17.5 results in 7 unique gene expression clusters from early to late pregnancy that define the landscape of molecular events in ongoing pregnancy. In the current dataset progesterone is predicted as an activated upstream regulator and maintainer of myometrial quiescence and is active till E10.5. Progesterone is predicted as an inhibited upstream regulator at E12.5. We identify 22 upstream regulators in the E10.5 to E12.5 time window where the switch to progesterone withdrawal occurs. They are putative relevant upstream activators of labour.

Metabolomics Approach to Investigate Estrogen Receptor-Dependent and Independent Effects of o,p'-DDT in the Uterus and Brain of Immature Mice

Previous studies have demonstrated the endocrine disruption of o,p'-DDT. In this study, we used a ¹H NMR based metabolomics approach to investigate the estrogenic effects of o,p'-DDT (300 mg/kg) on the uterus and brain after 3 days of oral gavage administration, and ethynylestradiol (EE, 100 μg/kg) was used as a positive control. A supervised statistical analysis (PLS-DA) indicated that o,p'-DDT exerted both estrogenic receptor-(ER)-dependent and independent effects on the uterus but mainly ER-independent effects on the brain at metabolome levels, which was verified by coexposing with the antiestrogenic ICI 182,780. Four changed metabolites-glycine, choline, fumarate, and phenylalanine-were identified as ER-independent alterations in the uterus, while more metabolites, including γ-aminobutyrate, N-acetyl aspartate, and some amino acids, were disturbed based on the ER-independent mechanism in the brain. Together with biological end points, metabolomics is a promising approach to study potential estrogenic chemicals.

THE EFFECT OF HORMONE TREATMENT ON THE PHOSPHORYLASE ACTIVITY OF THE RABBIT UTERUS

Glycogen and phosphorylase activity were identified in the uterus of hormone treated rabbits. Glycogen granules were very abundant in both layers of the myometrium following estrogen stimulation. In the ovariectomized, progesterone or estrogen-progesterone treated animals only a small number of glycogen granules was detected in the myometrium.

In the uteri of the rabbits treated with estrogen, phosphorylase activity was very intense in both layers of the myometrium. Only a trace of the enzyme was observed in the muscle layers of the animals treated with progesterone or with estrogen and progesterone. In the ovariectomized rabbits phosphorylase was observed in very small amounts in the outer part of the longitudinal layer.

Adiponectin, orexin A and orexin B concentrations in the serum and uterine luminal fluid during early pregnancy of pigs

Adiponectin is the most abundant adipose-released protein that circulates in human plasma at high concentrations. The neuropeptides orexin A (OXA, hypocretin-1) and orexin B (OXB, hypocretin-2) are derived from a common precursor peptide, prepro-orexin and are produced mainly by neurons located in the lateral hypothalamus. It has been demonstrated that the peptides such as adiponectin and orexins have an important role in the regulation of energy metabolism and neuroendocrine functions. These hormones appear to be implicated in both normal and disturbed pregnancy. The objectives of this study were to determine adiponectin and orexin concentrations in the plasma and uterine luminal fluid (ULF) of pigs during early gestation and to explore the relationships between hormone concentrations and stages of pregnancy. The greatest plasma concentrations of adiponectin were observed on days 15-16 and 27-28 of pregnancy, and the least concentrations were on days 30-32 of gestation and on days 10-11 of the oestrous cycle. In ULF, adiponectin concentrations were greater on days 15-16 of pregnancy and on days 10-11 of the oestrous cycle than on days 10-11 and days 12-13 of pregnancy. The greatest OXA concentrations in the blood plasma were noted on days 10-16 of gestation, and the least OXA concentrations were on days 27-32 of pregnancy and on days 10-11 of the oestrous cycle. Orexin A concentrations in ULF were greater on days 10-11 of the cycle than throughout pregnancy. Serum OXB concentrations were greatest on days 10-11 and 30-32 of pregnancy, and least on days 12-28 of gestation. The greatest OXB concentrations in ULF were on days 10-13 of gestation, and the least OXB concentrations were on days 15-16 of pregnancy. This is first study to demonstrate the presence of adiponectin and orexins in the serum and ULF during early pregnancy of pigs as well as the relationships between adiponectin and orexin concentrations and the stage of pregnancy. The fluctuations in adiponectin and orexin concentrations in the plasma and ULF suggest that the hormones present in ULF are mostly of local origin and that these hormones participate in the processes that accompany early pregnancy.

Prolactin role in the bovine uterus during adenomyosis

Adenomyosis is uterine dysfunction defined as the presence of endometrial glands within the myometrium. It is suggested that adenomyosis is estrogen-dependent pathology, and prolactin (PRL) also affects its development. In the uterus of ruminants, PRL stimulates gland proliferation and function. We hypothesized that in the bovine uterus, the expression of PRL and its receptors (PRLRs) during adenomyosis is disturbed and modulated by estradiol (E₂). Uterine tissues were collected postmortem from cows; epithelial, stromal, and myometrial cells were isolated; and cultured and treated with E₂. Material was divided into 2 groups: control (nonadenomyotic) and uteri with adenomyosis. In adenomyotic uterine tissue, PRL and its long-form receptor protein were increased, as determined by Western blotting. Immunohistostaining showed that during adenomyosis, PRL and its receptors are highly expressed in adenomyotic lesions. In cultured myometrial cells, protein expression of PRL and its receptors was increased during adenomyosis. Estradiol decreased PRLRs protein expression in nonadenomyotic stromal cells and in adenomyotic myometrial cells, and increased PRL secretion by adenomyotic myometrial cells. Moreover, PRL secretion was increased in untreated epithelial and stromal cells during adenomyosis. On the other hand, in stromal cells, PRLRs messenger RNA and protein expression was decreased, as determined by real-time PCR and Western blotting, respectively. Obtained results show that significant changes in PRL and PRLRs expression are observed in uterine tissue and cells during adenomyosis, which were also affected by E₂. These data suggest involvement of PRL in adenomyosis development and the link between PRL and E₂ actions during the dysfunction in cows.

Acute toxicity of quantum dots on late pregnancy mice: Effects of nanoscale size and surface coating

In this study, the effects of cadmium containing QDs (such as CdSe/ZnS and CdSe QDs) and bulk CdCl2 in pregnant mice, their fetuses, and the pregnancy outcomes were investigated. It was shown that although the QDs and bulk CdCl2 were effectively blocked by the placental barrier, the damage on the placenta caused by CdSe QDs still led to fetus malformation, while the mice in CdSe/ZnS QDs treatment group exhibited slightly hampered growth but showed no significant abnormalities. Moreover, the Cd contents in the placenta and the uterus of CdSe QDs and CdSe/ZnS QDs treatment groups showed significantly higher than the CdCl2 treated group which indicated that the nanoscale size of the QDs allowed relative ease of entry into the gestation tissues. In addition, the CdSe QDs more effectively altered the expression levels of susceptive genes related to cell apoptosis, dysplasia, metal transport, cryptorrhea, and oxidative stress, etc. These findings suggested that the nanoscale size of the QDs were probably more important than the free Cd in inducing toxicity. Furthermore, the results indicated that the outer surface shell coating played a protective role in the adverse effects of QDs on late pregnancy mice.

Expression of nerve growth factor and its receptors in the uterus of rabbits: functional involvement in prostaglandin synthesis

The aim of the present study was to evaluate: (1) the presence of nerve growth factor (NGF), neurotrophic tyrosine kinase receptor 1 (NTRK1), and nerve growth factor receptor (NGFR) in the rabbit uterus; and (2) the in vitro effects of NGF on PGF2α and PGE2 synthesis and on the PGE2-9-ketoreductase (PGE2-9-K) activity by the rabbit uterus. Nerve growth factor, NTRK1, and NGFR were immunolocalized in the luminal and glandular epithelium and stroma cells of the endometrium. reverse transcriptase polymerase chain reaction indicated the presence of messenger RNA for NGF, NTRK1, and NGFR in the uterus. Nerve growth factor increased (P < 0.01) in vitro secretions of PGF2α and PGE2 but coincubation with either NTRK1 or oxide nitric synthase (NOS) inhibitors reduced (P < 0.01) PGF2α production and blocked (P < 0.01) PGE2 secretion. Prostaglandins releases were lower (P < 0.01) than control when uterine samples were treated with NGF plus cyclooxygenase inhibitor. However, addition of NGFR inhibitor reduced (P < 0.01) PGF2α secretion less efficiently than NTRK1 or NOS inhibitors but had no effect on PGE2 yield. Nerve growth factor increased (P < 0.01) the activity of PGE2-9-K, whereas coincubation with NTRK1 or NOS inhibitors abolished (P < 0.01) this increase in PGE2-9-K activity. However, cotreatment with either cyclooxygenase or NGFR inhibitors had no effect on PGE2-9-K activity. This is the first study to document the distribution of NGF/NTRK1 and NGFR systems and their effects on prostaglandin synthesis in the rabbit uterus. NGF/NTRK1 increases PGF2α and PGE2 productions by upregulating NOS and PGE2-9-K activities, whereas NGF/NGFR augments only PGF2α secretion, through an intracellular mechanism that is still unknown.

DISTRIBUTION OF PHOSPHORYLASE IN THE UTERI OF CYCLIC AND HORMONE TREATED RATS

Following the technic of Takeuchi and Kuriaki, phosphorylase activity was identified in the uterus of cyclic and hormone treated rats. In the proestrous uterus phosphorylase activity was more pronounced in the outer longitudinal muscle layer than in the inner circular layer. In the diestrous as well as in the castrate uterus, enzymatic activity was observed in the outer longitudinal muscle layer, and only scattered amounts in the inner circular layer. Following estrogen treatment phosphoryhase activity was very pronounced in both layers, particularly in the outer longitudinal layer. In castrate progesterone-treated rats enzymatic activity was observed in the outer longitudinal layer. In rats that received estrogen and progesterone concurrently, phosphorylase activity was heavy in the outer longitudinal muscle layer and weak in the inner circular muscle layer.

In general, phosphorylase activity in the uterus of the rat corresponds to the distribution of glycogen in the rat uterus. However, enzymatic activity was observed in the uterus when glycogen was not detected by using the periodic acid-Schiff technic.

The distribution of glycogen in the rat uterus is discussed.

Activin A and follistatin during the oestrous cycle and early pregnancy in ewes

The activin pathway has been postulated to be involved in regulation of multiple reproductive processes important for survival of the conceptus. These processes include luteinisation of the follicular cells and thus function of the corpus luteum, early embryo development and uterine function including implantation of the conceptus. Therefore, the aim of the current study was to determine whether the concentrations of activin A and follistatin (FST), an activin-binding protein, differed between ewes with a lifetime history of enhanced or reduced embryonic survival (ES). The mRNAs encoding FST and activin A (inhibin beta A subunit; INHBA) were present in the uterus and abundant in the uterine luminal or glandular epithelia by day 18 of gestation. A peak of activin A was observed in the systemic circulation around the time of oestrus, and activin A concentrations were elevated in animals with reduced ES during the oestrous cycle and early gestation. Concentrations of activin A in uterine fluid were approximately twofold greater on day 16 of gestation in ewes with reduced ES compared to those with enhanced ES. No consistent differences in FST were observed between these groups. Treatment of luteinising ovine granulosa cells with activin A in vitro suppressed progesterone secretion providing evidence of a potential pathway whereby increased concentrations of activin A may decrease ES.

The protective effect of the proteasome inhibitor bortezomib on the uterus of ovariectomized rats

Bortezomib (BORT) is an anti-tumour agent that inhibits proteasome, which is responsible for the degradation of many intracellular proteins. Although some side-effects and chemotherapeutic effects of BORT are known, there has not been enough research regarding its effects on different tissues of proteasome inhibition in the senile period (post-menopausal). The aim of this study was to investigate the safety of using BORT during the post-menopausal period. The post-menopausal effects of BORT were investigated on ovariectomized (OVX) Spraque-Dawley rats. The female rats were separated into three groups: control, ovariectomized (OVX), and OVX + BORT. OVX and OVX + BORT groups consisted of six rats in each. BORT was administered intraperitoneally in a dosage of 0.2 mg/kg two days a week for four weeks after OVX. The uteri of the rats were investigated using morphometrical, histopathological, and immunohistopathological methods. A striking atrophy in the endometrium and myometrium was observed due to an estrogen deficiency in the OVX group. The partial protective effect of BORT administration was observed morphometrically and histopathologically. In immunohistochemical research, cytoplasmic NF-KB activity was observed in the presence of proteasome inhibition in the endometrium. In light of these findings, the limited protective effects of post-menopausal BORT administration are worth mentioning.

Uterine Carcinomas in Tetrabromobisphenol A-exposed Wistar Han Rats Harbor Increased Tp53 Mutations and Mimic High-grade Type I Endometrial Carcinomas in Women

Endometrial carcinoma is the most common gynecologic malignancy is the United States and accounts for 6% of all cancers in women. The disease is classified as type I or type II based on clinicopathologic and molecular features. It is a multifactorial disease with a number of risk factors, including environmental exposures. How environmental exposures, such as flame retardants, may affect the incidence of endometrial cancer is a topic of current and ongoing interest. Tetrabromobisphenol A (TBBPA) is a widely used brominated flame retardant found in a variety of household products. A recent 2-year National Toxicology Program carcinogenicity study found that exposure to TBBPA was associated with a marked increase in the development of uterine tumors, specifically uterine carcinomas, in Wistar Han rats. Molecularly, TBBPA-induced uterine carcinomas in Wistar Han rats were characterized by a marked increase in tumor protein 53 mutation compared to spontaneous uterine carcinomas, as well as overexpression of human epidermal growth factor receptor 2. Similar to spontaneous carcinomas, tumors in TBBPA-exposed rats were estrogen receptor-alpha positive and progesterone receptor negative by immunohistochemistry. The morphologic and molecular features of uterine carcinomas in TBBPA-exposed rats resemble those of high-grade type I tumors in women, and these data suggest that exposure to TBBPA may pose an increased cancer risk.

Melatonin-related genes expressed in the mouse uterus during early gestation promote embryo implantation

Melatonin, a superior antioxidant, is an important molecule which regulates female reproduction due to its receptor-mediated and receptor-independent antioxidant actions. In this study, we investigated the effect of melatonin on early gestation in a mouse model. During early gestation, the expression of the melatonin's rate-limiting enzyme, AANAT, gradually increased - in the uterus while the MT2 melatonin receptor was only expressed at day 2 of gestation and no MT1 was detected. Based on these findings, we conducted a melatonin injection experiment which demonstrated that 15 mg/kg melatonin significantly improved the number of implantation sites and the litter size. Also, the blastocyst and uterus were collected to identify the local action of melatonin. In the melatonin-treated mice, the endometrium was thicker than in the control mice; melatonin also caused an increase in density of uterine glands, and the uterine gland index (UGI) was significantly elevated over that of the control. Serum steroid hormone measurements revealed that at day 6 of gestation (postimplantation), melatonin significantly downregulated the E2 level, with no obvious effects on progesterone. Gene expression assay revealed that melatonin significantly upregulated expression of HB-EGF, a crucial gene involved in implantation as well as its receptor ErbB1 in the blastocyst. In addition, PRA, an important gene which influences the decidual response and luminal cell differentiation, p53, which regulates uterine through leukaemia inhibitory factor (LIF), were both increased after melatonin treatment. These data suggest that melatonin and its MT2 receptor influence early gestation. Exogenous melatonin treatment can improve mouse embryo implantation and litter size, which may have important applications in human reproductive health and animal husbandry.

Size dependent translocation and fetal accumulation of gold nanoparticles from maternal blood in the rat

BACKGROUND

There is evidence that nanoparticles (NP) cross epithelial and endothelial body barriers. We hypothesized that gold (Au) NP, once in the blood circulation of pregnant rats, will cross the placental barrier during pregnancy size-dependently and accumulate in the fetal organism by 1. transcellular transport across the hemochorial placenta, 2. transcellular transport across amniotic membranes 3. transport through ~20 nm wide transtrophoblastic channels in a size dependent manner. The three AuNP sizes used to test this hypothesis are either well below, or of similar size or well above the diameters of the transtrophoblastic channels.

METHODS

We intravenously injected monodisperse, negatively charged, radio-labelled 1.4 nm, 18 nm and 80 nm ¹⁹⁸AuNP at a mass dose of 5, 3 and 27 μg/rat, respectively, into pregnant rats on day 18 of gestation and in non-pregnant control rats and studied the biodistribution in a quantitative manner based on the radio-analysis of the stably labelled ¹⁹⁸AuNP after 24 hours.

RESULTS

We observed significant biokinetic differences between pregnant and non-pregnant rats. AuNP fractions in the uterus of pregnant rats were at least one order of magnitude higher for each particle size roughly proportional to the enlarged size and weight of the pregnant uterus. All three sizes of ¹⁹⁸AuNP were found in the placentas and amniotic fluids with 1.4 nm AuNP fractions being two orders of magnitude higher than those of the larger AuNP on a mass base. In the fetuses, only fractions of 0.0006 (30 ng) and 0.00004 (0.1 ng) of 1.4 nm and 18 nm AuNP, respectively, were detected, but no 80 nm AuNP (<0.000004 (<0.1 ng)). These data show that no AuNP entered the fetuses from amniotic fluids within 24 hours but indicate that AuNP translocation occurs across the placental tissues either through transtrophoblastic channels and/or via transcellular processes.

CONCLUSION

Our data suggest that the translocation of AuNP from maternal blood into the fetus is NP-size dependent which is due to mechanisms involving (1) transport through transtrophoblastic channels - also present in the human placenta - and/or (2) endocytotic and diffusive processes across the placental barrier.

Composition of the bovine uterine proteome is associated with stage of cycle and concentration of systemic progesterone

Early embryonic loss accounts for over 70% of total embryonic and foetal loss in dairy cattle. Early embryonic development and survival is associated with the concentration of systemic progesterone. To determine if the uterine proteome is influenced by stage of cycle or systemic progesterone concentrations, uterine flushings were collected from the ipsi- and contralateral uterine horns of beef heifers on Days 7 (n = 10) and 15 (n = 10) of the oestrous cycle. Animals were separated into low or high progesterone groups based on plasma progesterone concentrations on Day 5 of the cycle. Samples were albumin depleted before iTRAQ R labeling and subsequent strong cation exchange-LC-MS/MS analyses. A total of 20 proteins were up to 5.9-fold higher (p<0.05) and 20 were up to 2.3-fold lower on Day 15 compared toDay 7. In addition, the expression of a number of proteins on Day 7 and/or 15 of the cycle was correlated with progesterone concentrations during Days 3–7 or the rate of change in progesterone between Days 3 and 7. This study highlights the dynamic changes occurring in the microenvironment surrounding the embryo during this period. The findings here also support the hypothesis that progesterone supports embryonic development by altering the maternal uterine environment.

Dietary selenium influences calcium release and activation of MLCK in uterine smooth muscle of rats

We sought to elucidate the effects of different concentrations of dietary selenium on calcium ion release, MLCK levels, and muscle contraction in the uterine smooth muscle of rats. The selenium (Se) content of blood and of uterine smooth muscle tissues was detected by fluorescence spectrophotometry. Ca(2+) content was measured by atomic absorption spectroscopy. Calmodulin (CaM) and MLCK RNA and protein levels were analyzed by quantitative real-time polymerase chain reaction and Western blot, respectively. Dietary Se intake increased the Se levels in the blood and in uterine smooth muscle tissues and increased the Ca(2+) concentration in uterine smooth muscle tissues. The addition of Se also promoted CaM expression and enhanced MLCK activation in uterine smooth muscle tissues. In conclusion, Ca(2+), CaM, and MLCK were regulated by Se in uterine smooth muscle; Se plays a major role in regulating smooth muscle contraction in the uterus.

Utero-placental expression of angiotensin-(1-7) and ACE2 in the pregnant guinea-pig

BACKGROUND

In humans, trophoblast invasion, vascular remodeling and placental development are critical to determine the fate of pregnancy. Since guinea-pigs (GP) and humans share common pregnancy features including extensive trophoblast invasion, transformation of the uterine spiral arteries and a haemomonochorial placenta, the GP animal model was deemed suitable to extend our knowledge on the spatio-temporal immunoreactive expression of the vasodilator arpeptide of the renin-angiotensin system, angiotensin-(1-7) [Ang-(1-7)] and its main generating enzyme, angiotensin converting enzyme 2 (ACE2).

METHODS

Utero-placental units were collected in days 15, 20, 40 and 60 of a 64-67 day long pregnancy in 25 Pirbright GP. Ang-(1-7) and ACE2 expression in utero-placental units were evaluated by immunohistochemistry.

RESULTS

Ang-(1-7) and ACE2 were detected in the endothelium and syncytiotrophoblast of the labyrinthine placenta, interlobium, subplacenta, giant cells, syncytial sprouts, syncytial streamers, and myometrium throughout pregnancy. In late pregnancy, perivascular or intramural trophoblasts in spiral and mesometrial arteries expressed both factors. Immunoreactive Ang-(1-7) and ACE2 were present in decidua and in the vascular smooth muscle of spiral, myometrial and mesometrial arteries, which also express kallikrein (Kal), the bradykinin receptor 2 (B2R), vascular endothelial growth factor (VEGF) and its type 2 receptor (KDR), but no endothelial nitric oxide synthase (eNOS). In addition, the signal of Ang-(1-7) and ACE2 was especially remarkable in giant cells, which also show Kal, B2R. eNOS, VEGF and KDR.

CONCLUSIONS

The spatio-temporal expression of Ang-(1-7) and ACE2 in GP, similar to that of humans, supports a relevant evolutionary conserved function of Ang-(1-7) and ACE2 in decidualization, trophoblast invasion, vascular remodeling and placental flow regulation, as well as the validity of the GP model to understand the local adaptations of pregnancy. It also integrates Ang-(1-7) to the utero-placental vasodilatory network. However, its antiangiogenic effect may counterbalance the proangiogenic activity of some of the other vasodilator components.

Depth probing of diffuse tissues controlled with elliptically polarized light

Polarization gating is a popular technique in biomedical optics. It is widely used to inspect the surface of the tissues (under colinear or cocircular detection) or instead to probe the volume (cross-linear detection), without information on the probed depth. Elliptical polarization is introduced to explore the possibility of probing diffuse tissues at selective depths. A thorough Monte Carlo simulation study shows complete correlation between the probed depths and the ellipticity of the polarized light, for a medium with known optical properties. Within a wide range of optical parameters, a linear relation between the backscattered intensity and the depth extension of the probed volume was found whatever the polarization used, but with a controlled extension depending on the ellipticity.

The effect of sorafenib in postoperative adhesion formation in a rat uterine horn model

OBJECTIVE

Postoperative adhesions are a serious problem. In this study, we aimed to observe the effects of sorafenib in postoperative adhesions and, to examine the effects of sorafenib on tissue levels of vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF).

MATERIAL AND METHODS

Twenty female Wistar albino rats were randomized into two equal groups; sorafenib group (sorafenib treated) and control group; then all rats underwent laparotomy. Adhesions were developed by scalping on the anti-mesenteric surfaces of the right uterine horns. After 14 days, adhesions were investigated by using macroscopic, histopathological and immunohistochemical (for VEGF and PDGF) methods.

RESULTS

The sorafenib group had lower scores of total adhesions [1 (0-2.5) vs 1.5 (1-4); p: 0.037], staining of VEGF [1 (0-1) vs 1 (1-3); p: 0.029] and PDGF [1 (0-2) vs 2 (1-3); p: 0.006], and vascular proliferation [1 (0-2) vs 2 (1-3); p: 0.038] than the control group.

CONCLUSION

The findings of the present study show that sorafenib, a tyrosine kinase inhibitor, significantly reduced postoperative adhesion formation. This effect may be explained by inhibition of VEGF, PDGF, and thus vascular proliferation.

Analysis of fertility-related soluble mediators in human uterine fluid identifies VEGF as a key regulator of embryo implantation

Embryo implantation requires synchronized dialogue between the receptive endometrium and activated blastocyst via locally produced soluble mediators. During the midsecretory (MS) phase of the menstrual cycle, increased glandular secretion into the uterine lumen contains important mediators that modulate the endometrium and support the conceptus during implantation. This study aimed first to identify the growth factor and cytokine profile of human uterine fluid from fertile women during the midproliferative (MP; nonreceptive) and MS (receptive) phases of the cycle, and from women with unexplained infertility during the MS phase. The second aim was to determine important functions of endometrial secretions for embryo implantation. Analysis of uterine fluid using quantitative Luminex assays revealed the presence of over 30 cytokines and growth factors, of which eight [platelet-derived growth factor-AA, TNF-B, soluble IL-2 receptor-A, Fms-like tyrosine kinase 3 ligand, soluble CD40 ligand, IL-7, interferon-A2, and chemokine (C-X-C motif) ligand 1-3] were previously unknown in human uterine fluid. Comparison of the fertile MP, MS, and infertile MS cohorts revealed vascular endothelial growth factor (VEGF) levels are significantly reduced in uterine fluid during the MS phase in women with unexplained infertility compared with fertile women. Functional studies demonstrated that culturing mouse embryos with either MS-phase uterine fluid from fertile women or recombinant human VEGF significantly enhanced blastocyst outgrowth. Furthermore, treatment of human endometrial epithelial cells with uterine fluid or recombinant human VEGF-A significantly increased endometrial epithelial cell adhesion. Taken together, our data support the concept that endometrial secretions, including VEGF, play important roles during implantation. Identifying the soluble mediators in human uterine fluid and their actions during implantation provides insight into interactions essential for establishing pregnancy, fertility markers, and infertility treatment options.

SERPINE2, an inhibitor of plasminogen activators, is highly expressed in the human endometrium during the secretory phase

BACKGROUND

SERPINE2, also known as protease nexin-1, belongs to the serine protease inhibitor (SERPIN) superfamily. It is one of the potent SERPINs that modulates the activity of plasminogen activators (PAs). PAs and their SERPIN inhibitors, such as SERPINB2 and SERPINE1, were expressed in the human endometrium and were implicated in implantation. However, expression data about SERPINE2 in the human endometrium is still unknown. Thus, we conducted an investigation to reveal the spatiotemporal and cellular expression of SERPINE2 in the human uterus during the menstrual cycle.

METHODS

Seven patients who underwent a hysterectomy and samples of 120 archived patients' endometrial curettage or parts of the uterus that were formalin-fixed and embedded in paraffin. Western blotting was performed to evaluate the specificity and sensitivity of the antibody. Immunohistochemistry was conducted to localize the SERPINE2 expression site. Quantitative analysis was conducted to evaluate expression levels of SERPINE2 in various sub-phases of the menstrual cycle.

RESULTS

The SERPINE2 protein was primarily detected in the uterine fluid during the mid- and late-secretory phases of the menstrual cycle. It was predominantly expressed in the luminal and glandular epithelium, less in the myometrium, and only dispersedly in certain stromal cells throughout the menstrual cycle. A quantitative analysis of expression levels of SERPINE2 in the glandular epithelium revealed that it was highly expressed in the endometrium during the secretory phase compared to the proliferative phase.

CONCLUSIONS

The SERPINE2 protein is highly expressed in the endometrium during the secretory phase, indicating that it may participate in tissue remodeling involved in implantation.

The effects of estradiol and catecholestrogens on uterine glycogen metabolism in mink (Neovison vison)

Glycogen is a uterine histotroph nutrient synthesized by endometrial glands in response to estradiol. The effects of estradiol may be mediated, in part, through the catecholestrogens, 2-hydroxycatecholestradiol (2-OHE2) and 4-hydroxycatecholestradiol (4-OHE2), produced by hydroxylation of estradiol within the endometrium. Using ovariectomized mink, our objectives were to determine the effects of estradiol, 4-OHE2, and 2-OHE2 on uterine: 1) glycogen concentrations and tissue localization; 2) gene expression levels for glycogen synthase, glycogen phosphorylase, and glycogen synthase kinase-3B; and 3) protein expression levels for glycogen synthase kinase-3B (total) and phospho-glycogen synthase kinase-3B (inactive). Whole uterine glycogen concentrations (mean ± SEM, mg/g dry wt) were increased by estradiol (43.79 ± 5.35), 4-OHE2 (48.64 ± 4.02), and 2-OHE2 (41.36 ± 3.23) compared to controls (4.58 ± 1.16; P ≤ 0.05). Percent glycogen content of the glandular epithelia was three-fold greater than the luminal epithelia in response to estradiol and 4-OHE2 (P ≤ 0.05). Expression of glycogen synthase mRNA, the rate limiting enzyme in glycogen synthesis, was increased by 4-OHE2 and 2-OHE2 (P ≤ 0.05), but interestingly, was unaffected by estradiol. Expression of glycogen phosphorylase and glycogen synthase kinase-3B mRNAs were reduced by estradiol, 2-OHE2, and 4-OHE2 (P ≤ 0.05). Uterine phospho-glycogen synthase kinase-3B protein was barely detectable in control mink, whereas all three steroids increased phosphorylation and inactivation of the enzyme (P ≤ 0.05). We concluded that the effects of estradiol on uterine glycogen metabolism were mediated in part through catecholestrogens; perhaps the combined actions of these hormones are required for optimal uterine glycogen synthesis in mink.

Interaction of zearalenone and soybean isoflavone on the development of reproductive organs, reproductive hormones and estrogen receptor expression in prepubertal gilts

The aim of the present study was to investigate the interactive effect of zearalenone (ZEA) and soybean isoflavone (ISO) on the development of reproductive organs, reproductive hormones and estrogen receptor expression in prepubertal gilts. Ninety 75-day-old female pigs (Duroc × Landrace × Yorkshire, 26.50 ± 0.60 kg) were randomly allocated to nine diet treatments during the 21 day study. The experiment employed a 3 × 3 factorial design using a non-soybean meal diet with addition of 0, 0.5 or 2.0mg/kg ZEA and 0, 300 or 600 mg/kg ISO. The results indicated that diets supplemented with 600 mg/kg ISO could reduce the increased weight of the reproductive organs induced by ZEA at 2mg/kg (P<0.05) while feed containing ISO and 0.5mg/kg ZEA increased the weight of the reproductive organs compared with pigs fed diets with 0.5mg/kg ZEA alone. Diets with ISO at 600 mg/kg reduced the large width of vulvas induced by diets with 2mg/kg ZEA (P<0.05). Simultaneous provision of ZEA and ISO to prepubertal gilts increased the level of E2 at days 7 and 14, but decreased it at day 21 (P<0.05). Pigs simultaneously fed 2mg/kg ZEA and 600 mg/kg ISO had the highest level of FSH (P<0.05). There was a significant interaction (P<0.05) between ZEA and ISO supplementation on the level of LH, and pigs offered diets with 2mg/kg ZEA and 600 mg/kg ISO had the lowest level of LH on days 14 and 21. Animals supplemented simultaneously with ZEA and ISO showed higher ERα/ERβ mRNA expression compared to those offered diets containing 0.5mg/kg ZEA alone or basal diets. However, this simultaneous supplementation resulted in a lower level of ERα/ERβ mRNA expression compared to offering diets with 2mg/kg ZEA alone. It appears that ISO can counteract the estrogenic influence of a high dosage of ZEA (2mg/kg). This affect might be attributed to competitive binding with estrogen receptors, thereby weakening the estrogenic effect of ZEA. Meanwhile, interactions between ZEA and ISO may interfere with the functioning of E2, FSH and LH in prepubertal gilts.

Distribution and quantitative changes in amounts of aquaporin 1, 5 and 9 in the pig uterus during the estrous cycle and early pregnancy

BACKGROUND

Aquaporins (AQPs) are a family of membrane channel proteins that facilitate bulk water transport. To date, 11 isoforms of AQPs have been reported to be expressed in the female and male reproductive systems. The purpose of our study was to determine the localization and quantitative changes in the expression of AQP1, 5 and 9 within the pig uterus during different stages of the estrous cycle and early pregnancy.

METHODS

Immunoperoxidase and semi-quantitative immunoblotting techniques were used to examine the distribution and changes in amounts of AQP1, AQP5 and AQP9 in uteral cells of pigs at the early (Days 2-4), middle (10-12), late (14-16) stage of the luteal phase and late (18-20) stage of the follicular phase of the estrous cycle as well as on Days 14-16 and 30-32 of gestation (the onset and the end of implantation process).

RESULTS

The results demonstrated that AQP1, 5, and 9 were clearly detected in all studied stages of the estrous cycle and pregnancy. AQP1 was localized within uterine blood vessels. In cyclic gilts, endometrial and myometrial expression of AQP1 protein did not change significantly but increased during gestation. AQP5 was localized in smooth muscle cells and uterine epithelial cells. Endometrial expression of AQP5 protein did not change significantly between Days 2-4 and 10-12 of the estrous cycle but increased on Days 14-16 and 18-20 as well as during early pregnancy. Myometrial expression of AQP5 did not differ significantly during the estrous cycle but increased in the pregnancy. The anti-AQP9 antibody labeled uterine epithelial cells of uterus. Endometrial expression of AQP9 did not change significantly between Days 2-4 and 10-12 of the estrous cycle but increased on Days 14-16 and 18-20 as well as during early pregnancy.

CONCLUSIONS

The results suggest that a functional and distinctive collaboration exists among diverse AQPs in water handling during the different uterine phases in the estrous cycle and early pregnancy.

Effect of estrus induction on prostaglandin content and prostaglandin synthesis enzyme expression in the uterus of early pregnant pigs

Prostaglandins (PGs) play a pivotal role in maternal recognition of pregnancy and implantation in pigs. In the present study, PGE(2), PGF(2alpha), and PGFM (PGF(2alpha) metabolite) content, as well as PGE(2) synthase (mPGES-1) and PGF(2alpha) synthase (PGFS) expression was investigated in early pregnant gilts with natural (n=21) and PMSG/hCG-stimulated (n=19) estrus. Endometrial tissue samples, uterine luminal flushings (ULFs), and blood serum were collected on days 10-11, 12, and 15 after insemination. Additionally, day 15 conceptuses were collected for mPGES-1 and PGFS protein expression. Effect of estrus induction was observed on day 15 of pregnancy, when the content of PGE(2) in the uterine lumen was fourfold lower in gonadotropin-stimulated gilts in comparison to controls (P<0.001). Decreased PGE(2) content in ULFs of gonadotropin-treated pigs was preceded by lower endometrial mPGES-1 gene expression in hormonally-stimulated animals in comparison to control gilts (P<0.01). On the other hand, estrus induction with PMSG/hCG resulted in higher PGE(2) accumulation in the endometrial tissue on day 15 of pregnancy (P<0.01). Furthermore, PGF(2alpha) content in the endometrium and PGFM levels in blood serum were lower in gonadotropin-treated gilts, especially on day 12 after insemination when compared to control gilts (P<0.01). Finally, PGFS expression in day 15 conceptuses was decreased in animals with hormonally-induced estrus. We conclude that PMSG/hCG stimulation of prepubertal gilts to induce estrus results in changes of PG production and secretion during early pregnancy, which, in turn, may affect conceptus development, implantation, and the course of pregnancy.

Clock gene expression in gravid uterus and extra-embryonic tissues during late gestation in the mouse

Evidence in humans and rodents suggests the importance of circadian rhythmicity in parturition. A molecular clock underlies the generation of circadian rhythmicity. While this molecular clock has been identified in numerous tissues, the expression and regulation of clock genes in tissues relevant to parturition is largely undefined. Here, the expression and regulation of the clock genes Bmal1, Clock, cryptochrome (Cry1/2) and period (Per1/2) was examined in the murine gravid uterus, placenta and fetal membranes during late gestation. All clock genes examined were expressed in the tissues of interest throughout the last third of gestation. Upregulation of a subset of these clock genes was observed in each of these tissues in the final two days of gestation. Oscillating expression of mRNA for a subset of the examined clock genes was detected in the gravid uterus, placenta and fetal membranes. Furthermore, bioluminescence recording on explants from gravid Per2::luciferase mice indicated rhythmic expression of PER2 protein in these tissues. These data demonstrate expression and rhythmicity of clock genes in tissues relevant to parturition indicating a potential contribution of peripheral molecular clocks to this process.

[Collagen histomorphometric evaluation in uterin tissue samples before and after treatment of uterine fibroids with arterial embolization]

PURPOSE

To analyze histomorphometric consequences of the uterine arteries embolization (UAE) in the uterine tissue, especially by collagen tissue quantification through uterine biopsy, before and after treatment of uterine leiomyoma.

METHODS

15 patients with symptomatic leyomioma and/or infertility, submitted to UAE, participated in the study according to the study exclusion criteria, after having signed an informed consent. Uterine biopsy was performed in the secretory phase of the menstrual cycle, before and three months after the procedure, to evaluate the collagen. After the histological processing of the material, 3 micro slices were prepared, some of them dyed with hematoxiline-eosin (HE) and others with the specific dye for collagen fibers (Picrosirius red). Then, the slides were examined and interpreted, and the collagen quantified. The amount was calculated as the percent of the area composed by collagen, and the result expressed in mean+/-standard deviation (SD). Data has then been submitted to statistical analysis by Student's paired t test (p<0.05).

RESULTS

The presence of smooth muscle cells was observed in the biopsies performed before the treatment, surrounded by a rich network of collagen fibers, which are part of the tumor, blood vessels and fibroblast nuclei. On the slides of biopsies performed after the treatment, it was observed the presence of widespread coagulation necrosis, vascular thrombosis, calcification and lymphoplasmocitary infiltration areas and clear reduction of the collagen component. The percentage of collagen fibers was higher in the pre-UAE group (84.07+/-1.41), than in the post-UAE (81.05+/-1.50) group, with p<0.0001, and 95% confidence interval (CI95%) from 2.080 to 3.827.

CONCLUSION

The quantitative and qualitative collagen reduction clearly shows that the proposed treatment is efficient in reducing the tumoral mass, composed mainly by collagen fibers intermingled with neoplasic smooth muscle cells. Nevertheless, complementary studies are needed to investigate the functional and biological consequences of these histological changes.

Estrogen modulates expression of putative housekeeping genes in the mouse uterus

Estrogens regulate gene expression and cell proliferation in target tissues. In studies of estrogen-regulated gene expression, identification of appropriate housekeeping genes (HKGs), reference genes whose expression is not altered by treatment, is difficult. The goal of this study was to define HKGs unaltered by estrogen in the mouse uterus. Ovariectomized C57BL6 mice were dosed with 20 micrograms/kg ethinylestradiol and the uterus was collected at 6, 24, and 72 h later to bracket the biphasic time course of estrogen action in the rodent uterus. RNA was isolated, cDNA synthesized and equal amounts of cDNA were added to real-time PCR reactions. The expression of seven out of nine putative HKGs was altered by estrogen in the mouse uterus. Estrogen induced four gene expression profiles, expression of: (1) Actb and Hsp90ab1 were up-regulated early, (2) B2m and Gusb were up-regulated late, (3) Gapdh, Hprt1, and Ppia were up regulated at all time points, and (4) Rpl13a and 18srRNA were unaltered. This highlights the need to empirically determine the appropriate HKG for each experimental condition. Based on these results, we suggest using Rpl13a or 18srRNA as HKGs for xenoestrogen studies in the mouse uterus and as good candidates to test under different experimental conditions.

Histopathological and molecular evaluation of Holstein-Friesian cows postpartum: toward an improved understanding of uterine innate immunity

Bovine uterine disease reduces milk yield, impairs fertility and has implications for animal welfare. During involution, the uterus is usually exposed to multiple potential bacterial pathogens which are cleared by successful orchestration of the local inflammatory response. Unsuccessful resolution leads to the development of disease. The aim of this study was to characterize the local innate immune response in the uterus during physiological involution using histopathological and molecular analyses in 9 cows, 2 weeks after calving (early postpartum, EPP), and 4 cows, 9 weeks after calving (late postpartum, LPP). Uterine biopsies taken from each cow were classified by histopathology, and RNA was extracted for molecular analysis. Two EPP cows were classified with a mild, 5 with a moderate and 2 with a severe inflammatory response. Relative gene expression analysis was then performed using quantitative real-time PCR (qRT-PCR) and specific primers for genes encoding Toll-like receptors (TLRs), chemokines, cytokines, acute phase proteins (APPs) and antimicrobial peptides (AMPs). TLR4, transcription factor NFKB1 and the inflammatory cytokines IFNG, IL1A, IL6, IL8, IL12A were all significantly increased in EPP cows (P<0.05). Increase in HP, SAA3, TAP and DEFB5 genes was particularly marked in cows with severe inflammation. These results reveal evidence of an inflammatory uterine environment in the early postpartum period with significant induction of both AMP and APP genes. Histopathological grades in EPP cows are underpinned by quantitative changes in gene expression. Understanding the molecular mechanisms contributing to uterine immunity in the early postpartum period may identify candidate genes associated with the resolution of inflammation.

Exposure to persistent organic pollutants in utero and related maternal characteristics on birth outcomes: a multivariate data analysis approach

Persistent organic pollutants (POPs) have the capacity to pass through the placental barrier and into the fetal blood stream, and pose health risks to fetuses and neonates who are believed to be more vulnerable to the effects of environmental pollutants. In this study, the prevalence of POPs, including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated biphenyl ethers (PBDEs), were determined in 41 cord blood samples collected during the year 2006 in Singapore. The effects of these xenobiotics and the maternal characteristics on fetal growth and development were explored using multivariate data analysis (MVA) techniques, including partial least-squares regression (PLSR) and discriminant analysis (PLS-DA). POPs were found in all cord blood samples, corroborating the transplacental transfer (TPT) of these xenobiotics. Chlordanes and PCBs were observed to have adverse effects on fetal growth (i.e. birth weight, length, head circumference) and health (as indicated by Apgar scores), indicating the chemical exposure in utero could also be deemed as an influential factor on fetal growth, even at the normal doses in general population. Maternal height, weight, ethnicity, dietary habits and lifestyle were also the determinants for the neonatal variables. Exposure to POPs may alter maternal hormone levels, which could regulate the offspring sex. Trans-chlordane, p,p'-DDE, p,p'-DDT and PCB 138 and 158 were speculated as testosterone triggers which lead to more baby boys, while the effects of beta-HCH and PCB 180 were opposite.

Gonadotropin releasing hormone receptor gene and protein expression and immunohistochemical localization in bovine uterus and oviducts

Recently GnRH, GnRH-R systems has been demonstrated in various extrahypothalamic and extrapituitary reproductive tissues in different mammalian species, where GnRH acts in an autocrine and or paracrine manner and modulates different biological processes. GnRH-R mRNA has also been demonstrated in bovine ovaries (follicle and corpus luteum) and normal and carcinogenic human endometrium/endometrial cells. This is the first study elucidating presence of GnRH-R mRNA and GnRH-R protein in bovine uterus and oviducts in follicular and luteal phases of the estrous cycle and further localizing the receptors to endometrial and oviductal epithelial cells. To our knowledge this is the first report demonstrating GnRH-R mRNA and protein in mammalian oviducts. We used gene-specific primers and monoclonal GnRH-R antibody to test GnRH-R mRNA and GnRH-R protein through RT-PCR and immunobloting. Immunohistochemistry was employed to localize these receptors to endometrial and oviductal epithelial cells. GnRH-R mRNA and receptor protein were expressed at expected molecular weights of 920bp and 60kD, respectively. Densitometry analysis revealed that expression levels for GnRH-R protein in uterus and oviducts were similar to bovine pituitary. The presence of GnRH receptors in bovine uterus and oviducts is intriguing and it would be imperative to examine the functional role of this system in the regulation of reproductive processes.

Effect of preovulatory concentrations of estradiol and initiation of standing estrus on uterine pH in beef cows

Previous studies have indicated that initiation of standing estrus within 24h of fixed-time AI influenced pregnancy rates. Furthermore, uterine environment at time of insemination can influence sperm transport. We hypothesized that preovulatory concentrations of estradiol would influence uterine pH at time of insemination. The objective of this study was to determine the influence of elevated preovulatory concentrations of estradiol on uterine pH following a fixed-time AI protocol. Cows were synchronized with the CO-Synch (n=57) protocol, and 29 cows were treated with an injection of estradiol cypionate (ECP; 1mg) 36h before the second injection of GnRH. Cows that exhibited standing estrus or were treated with ECP had increased (P<0.05) concentrations of estradiol compared to cows not in estrus and not administered ECP, respectively. There was an ECP by standing estrus interaction on uterine pH (P=0.01). Control cows that exhibited estrus had a reduced uterine pH (6.72+/-0.10; P=0.05) compared to control cows not exhibiting estrus (7.0+/-0.06). Cows treated with ECP and detected in standing estrus had a greater uterine pH (7.0+/-0.07) compared to control cows in estrus (P=0.02) and ECP cows not in estrus (6.81+/-0.09; P=0.06). The interval between the initiation of standing estrus and when pH was determined also influenced uterine pH. Cows that initiated standing estrus within 4h of pH determination had a lower uterine pH (6.74+/-0.12) compared to cows that initiated estrus 4-8h (7.09+/-0.08; P=0.07) or 8-12h (7.10+/-0.15; P=0.03) after pH determination. In summary, elevated concentrations of estradiol influenced standing estrus but only influenced uterine pH when pH was determined within 4h of the initiation of standing estrus.

Concentration and composition of free amino acids and osmolalities of porcine oviductal and uterine fluid and their effects on development of porcine IVF embryos

The concentration of free amino acids and the osmolalities in porcine oviductal (OF) and uterine fluids (UFs) on day 3 (D3) and day 5 (D5) were measured by HPLC and Vapor Pressure Osmometer, respectively. Based on these measurements we designed new media based on PZM3 by modifying the amino acid composition and osmolality. The effectiveness of the modified PZM3 on the development of porcine IVF embryos was then investigated. A total of 24 free amino acids were measured, including 20 protein and 4 nonprotein amino acids (beta-alanine, taurine, ornithine, and citrulline). There was no significant difference in the total concentration of amino acids among D3OF (13.06 +/- 3.63 mmol/L), D3UF (10.54 +/- 5.16 mmol/L), or D5UF (10.23 +/- 6.69 mmol/L). But the total concentration of amino acids in D5OF (5.89 +/- 1.47 mmol/L) was significantly lower than the three fluids above. Some individual amino acids varied significantly depending on where they were collected and from which day. The blastocyst rates of porcine IVF embryos were not improved when embryos were cultured in PZM3 with amino acids at D3OF (PZM3-D3OF, 20.3 +/- 7.9%) or D5UF (PZM3-D5UF, 14.3 +/- 10.7%) concentrations or in PZM3-D3OF for the first 48 (20.5 +/- 15.1), 72 (25.6 +/- 10.4), and 96 (18.7 +/- 10.0) hr and then transferred into PZM3-D5UF compared with PZM3 with Sigma amino acid solution (PZM3-SAA) (30.8 +/- 9.1%). However, when IVF embryos were cultured in PZM3-D5UF, the average nuclear number per blastocyst (57.6 +/- 8.3) was increased compared to PZM3-SAA (40.5 +/- 3.5). The osmolalities in D3OF, D3UF, D5OF, and D5UF were 318 +/- 8, 320 +/- 32, 321, and 293 +/- 8 mOsM, respectively. When the IVF embryos were cultured in PZM3-SAA and PZM3-D3OF at a variety of osmolalities (150-360 mOsM), higher blastocyst rates were obtained at 270-300 mOsM in the PZM3-SAA group (24.6-33.9%) and 270-290 mOsM in PZM3-D3OF group (22.4-24.2%). The blastocyst rate gradually decreased when the osmolality was increased or decreased in both groups. When the embryos were cultured in PZM3-SAA at 330 mOsM for the first 72 hr and then transferred to 250 mOsM (33.3 +/- 3.4%), the blastocyst rate was higher than original PZM3 (21.2 +/- 2.2%) (288 mOsM).

Maternal disturbance in activated sphingolipid metabolism causes pregnancy loss in mice

Uterine decidualization, a process that occurs in response to embryo implantation, is critical for embryonic survival and thus is a key event for successful pregnancy. Here we show that the sphingolipid metabolic pathway is highly activated in the deciduum during pregnancy and disturbance of the pathway by disruption of sphingosine kinase (Sphk) genes causes defective decidualization with severely compromised uterine blood vessels, leading to early pregnancy loss. Sphk-deficient female mice (Sphk1(-/-)Sphk2(+/-)) exhibited both an enormous accumulation of dihydrosphingosine and sphingosine and a reduction in phosphatidylethanolamine levels in pregnant uteri. These mice also revealed increased cell death in decidual cells, decreased cell proliferation in undifferentiated stromal cells, and massive breakage of decidual blood vessels, leading to uterine hemorrhage and early embryonic lethality. Thus, sphingolipid metabolism regulates proper uterine decidualization and blood vessel stability. Our findings also suggest that disturbance in sphingolipid metabolism may be considered as a cause of pregnancy loss in humans.

Gonadotropin-dependent regulation of bovine pituitary adenylate cyclase-activating polypeptide in ovarian follicles prior to ovulation

To study the regulation of bovine pituitary adenylate cyclase-activating polypeptide (PACAP) in preovulatory follicles prior to ovulation, PACAP cDNA was isolated by RT-PCR. Its open reading frame (ORF) is composed of 531 bp, and encodes for a 176-amino acid protein that bears 76-90% identity with other PACAP homologs. Using bovine preovulatory follicles obtained between 0 and 24 h after human chorionic gonadotropin (hCG) and semiquantitative RT-PCR/Southern blot, we demonstrate that levels of PACAP mRNA were low at 0 h, markedly increased at 6 and 12 h (P<0.05), and declined 18 and 24 h after hCG. Levels of PACAP mRNA were high in the bovine pituitary, testis, intestine and uterus, but moderate to low in other tissues. Analyses performed on isolated preparations of granulosa and theca cells showed a significant increase of PACAP transcripts in both cell types after hCG, whereas primary granulosa cell cultures revealed high levels of PACAP as well as its receptors PAC-1 and VPAC-2 mRNA after forskolin treatment. Overexpression of the catalytic subunit of protein kinase A (PKA) in granulosa cells stimulated, but treatment with H89 or PKA inhibitor protein inhibited PACAP mRNA expression, whereas PACAP overexpression stimulated an increase in abundance of transcripts for PGHS-2, PGES, EP2 receptor, progesterone receptor, and ADAMTS-1, but not for P450-side chain cleavage and P450 aromatase. Thus, this study demonstrates the gonadotropin-dependent regulation of PACAP mRNA in bovine preovulatory follicles, the importance of PKA activation in the expression of PACAP in granulosa cells, and stimulating effect of PACAP on gene expression during the ovulatory process.

Changes in major proteins in the embryonic capsule during immobilization (fixation) of the conceptus in the third week of pregnancy in the mare

During the third week of pregnancy, the equine conceptus is enclosed within a capsule, the glycan composition of which changes at around day 16 (ovulation = day 0) when the conceptus becomes immobilized (fixed) in the uterine lumen. Our objective was to characterize the process of fixation by identifying changes in major capsule-associated proteins. Individual equine conceptuses (n = 55) were collected transcervically by uterine lavage between days 13.5 and 26.5. Major proteins extracted from capsules were compared with those in fluids from the uterus and yolk sac by SDS-PAGE. Until day 14, a major capsule-associated protein that migrated at approximately 10 kDa was identified by N-terminal sequencing as equine beta2 microglobulin (beta2M). During fixation, beta2M in the capsule underwent limited proteolysis to an approximately 8 kDa form lacking nine amino acids from the N terminus, and was subsequently degraded. Expression of beta2M mRNA was detected in the yolk-sac wall tissues and endometrium between days 13.5 and 17.5. During this period, beta2M in the capsule was evidently not part of a complex with major histocompatibility complex class 1 heavy alpha chain bands because these were undetectable in the capsule and uterine lavage. Uterocalin (p19) was detected in uterine lavage and capsule throughout fixation, but in yolk-sac fluid only before fixation. These studies indicate that intact beta2M is a major protein associated with the embryonic capsule before fixation, after which it undergoes limited proteolysis to a truncated approximately 8 kDa form that remains in the capsule after the conceptus is immobilized.

Uterine stretch regulates temporal and spatial expression of fibronectin protein and its alpha 5 integrin receptor in myometrium of unilaterally pregnant rats

The adaptive growth of the uterus during pregnancy is a critical event that involves increased synthesis of extracellular matrix (ECM) proteins and dynamic remodeling of smooth muscle cell (SMC)-ECM interactions. We have previously found a dramatic increase in the expression of the mRNAs that encode fibronectin (FN) and its alpha5-integrin receptor (ITGA5) in pregnant rat myometrium near to term. Since the myometrium at term is exposed to considerable mechanical stretching of the uterine wall by the growing fetus(es), the objective of the present study was to examine its role in the regulation of FN and ITGA5 expression at late gestation and during labor. Using myometrial tissues from unilaterally pregnant rats, we investigated the temporal changes in Itga5 gene expression in gravid and empty uterine horns by Northern blotting and real-time PCR, in combination with immunoblotting and immunofluorescence analyses of the temporal/spatial distributions of the FN and ITGA5 proteins. In addition, we studied the effects of early progesterone (P4) withdrawal on Itga5 mRNA levels and ITGA5 protein detection. At all time-points examined, the Itga5 mRNA levels were increased in the gravid uterine horn, compared to the empty horn (P < 0.05). Immunoblot analysis confirmed higher ITGA5 and FN protein levels in the myometrium, associated with gravidity (P < 0.05). Immunodetection of ITGA5 was consistently high in the longitudinal muscle layer, increased with gestational age in the circular muscle layer of the gravid horn, and remained low in the empty horn. ITGA5 and FN immunostaining in the gravid horn exhibited a continuous layer of variable thickness associated directly with the surfaces of individual SMCs. In contrast to the effects of stretch, P4 does not appear to regulate ITGA5 expression. We speculate that the reinforcement of the FN-ITGA5 interaction: 1) contributes to myometrial hypertrophy and remodeling during late pregnancy; and 2) facilitates force transduction during the contractions of labor by anchoring hypertrophied SMCs to the uterine ECM.

Granulocyte-macrophage colony stimulating factor and interleukin-8 in the reproductive tract of ewes following oestrus and mating

Cytokines produced in the female reproductive tract after mating may enhance reproductive success. The present study investigated the distribution of granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin (IL)-8 in tissues and luminal secretions from different sites in the reproductive tract of the ewe following oestrus and after natural mating. Fifteen ewes were mated with a ram for 1 h and their reproductive tracts collected 3, 6, 18, 24 or 48 h later. Another 15 ewes were used as oestrous controls. Luminal secretions and tissue samples were collected from seven sites in each reproductive tract. Secretions were analysed by enzyme-linked immunosorbent assay and tissues were stained immunohistochemically using anti-sheep GM-CSF and anti-sheep IL-8 antibodies. Both cytokines were found in luminal and glandular endometrial epithelium and, to a lesser extent, in cervical epithelium; neither was found in the vaginal epithelium. Twice as many (P < 0.05) luminal samples from mated ewes than non-mated ewes were positive for GM-CSF. The vaginal lumen contained significantly higher (P < 0.01) concentrations of IL-8 compared with other sites, irrespective of mating status. Significant differences (P < 0.05) were found in staining intensity of GM-CSF and IL-8 from different sites. Production of GM-CSF and IL-8 by reproductive tissues is likely to contribute to leucocyte infiltration into the ovine reproductive tract.

Expression of PAX2 in papillary serous carcinoma of the ovary: immunohistochemical evidence of fallopian tube or secondary Müllerian system origin?

PAX2 is a urogenital developmental transcription factor expressed in the Wolffian ducts, developing kidneys, and Müllerian ducts during embryonic stage. Its function in renal development is well documented and its clinical application in the diagnosis of lesions of renal origin has been reported recently. However, information on its role in the Müllerian-derived genital tract is sparse. In this study, we investigated the expression of PAX2 in human female genital tract using immunohistochemistry. We demonstrated that PAX2 was expressed specifically in the epithelial cells of fallopian tube, endometrial and endocervical glands, but not in the stromal tissues in these areas. PAX2 was detected in secondary Müllerian structures in the ovary, such as endometriotic and endosalpingiotic glands and rete ovarii, but not in ovarian surface epithelium, surface epithelium-derived inclusion cysts, stroma, or sex-cord-derived structures such as follicles, oocytes, and corpus luteum. In addition, PAX2 was detected in 67% of ovarian papillary serous carcinomas (N=36) but rarely in peritoneal malignant mesotheliomas, with two exceptions (N=54). Interestingly, the two PAX2-positive 'peritoneal malignant mesotheliomas' were from female patients and were positive for estrogen receptor. The significance of expression of PAX2 and estrogen receptor in these cases is under investigation. Taken together, we suggest that PAX2 is a novel Müllerian-specific epithelial marker when used in proper clinical settings. Identification of PAX2 in the majority of papillary serous carcinomas of the ovary but not in the ovarian surface epithelium or epithelium-derived inclusion cysts suggests that this malignant epithelial tumor may be directly derived from the primary or secondary Müllerian epithelium in or surrounding the ovary, rather than from the surface epithelium or its derivatives.

Wild Fulvous Fruit Bats (Rousettus leschenaulti) Exhibit Human-Like Menstrual Cycle1

We investigated the menstrual cycle of wild fulvous fruit bats (Rousettus leschenaulti), focusing on changes in the endometrial and ovarian structure and pituitary and steroid hormones. The menstrual cycle lasts for 33 days in bats studied in their natural habitat and in captivity. Vaginal bleeding was restricted to a single day (Day 1). A preovulatory follicle was found in the ovary on Day 18 when the levels of LH and FSH reached their maxima, accompanied by a thickened endometrium. On Day 24, serum levels of progesterone and estradiol-17 were also maximal, and uterine glands increased in size. After that, the levels of progesterone dropped precipitously, leading to menstrual bleeding. Both the morphologic and hormonal changes observed in fulvous fruit bats during the menstrual cycle resemble similar changes in humans. Fulvous fruit bats may be useful nonprimate laboratory models to study menstruation and menstrual dysfunction.