Biogenic monoamines in preimplantation development

Serotonin Signaling in Mouse Preimplantation Development: Insights from Transcriptomic and Structural-Functional Analyses

Serotonin (5-HT), a versatile signaling molecule, plays a variety of roles in both neurotransmission and tissue regulation. The influence of serotonin on early development was first studied in marine invertebrate embryos and has since been documented in a variety of vertebrate species, including mammals. The present study investigates the expression and functional activity of serotonin components in mouse embryos, focusing on key receptors and transporters. Transcriptomic analyses revealed that mRNA transcripts related to serotonin show marked expression during the oogenesis and preimplantation stages. The results of the immunohistochemical studies show the presence of serotonin, the vesicular monoamine transporter VMAT2, and several membrane receptors (5-HT1B, 5-HT1D, 5-HT2B, 5-HT7) in the early stages of development. A functional analysis performed with the VMAT inhibitor reserpine revealed the crucial role of vesicular transport in the maintenance of serotonin signaling. The findings presented here support the hypothesis that serotonin plays a significant role in oocyte maturation and embryonic development, as well as in interblastomere interactions.

Gamma-aminobutyric acid (GABA) can affect physiological processes in preimplantation embryos via GABAA and GABAB receptors

Purpose

Several widely used substances (e.g., some therapeutics or food supplements) can act on gamma-aminobutyric acid (GABA) receptors, and we investigated whether the activation of these receptors could affect the preimplantation embryo.

Methods

Transcripts of all GABA receptor subunits and selected proteins were examined using quantitative RT-PCR and immunohistochemistry. To analyze the effects of receptor activation, in vitro culture of mouse preimplantation embryos with natural and synthetic GABA receptor ligands was used.

Results

We detected nine GABA receptor transcripts in mouse blastocysts and 14 GABA receptor transcripts in ovulated oocytes. The results of this study indicate that ionotropic GABA_A receptors can be formed from α5, β3, and γ3 (or δ, π) subunits, GABA_A-ρ receptors can be formed from ρ2 subunits and metabotropic GABA receptors can be formed from GABA_B1b and GABA_B2 subunits in mouse blastocysts. Supplementing the culture medium with GABA at concentrations of 2-10 mM or with specific GABA_A and GABA_B receptor agonists (at concentrations of 10-100 μM) significantly increased the proportion of dead cells in blastocysts. The GABA-induced effects were prevented by pretreatment of embryos with GABA_A and GABA_B receptor antagonists.

Conclusion

The results of this study indicate that GABA and synthetic GABA receptor ligands can negatively affect preimplantation embryos via GABA_A and GABA_B receptors.

Analysis of the Amine Submetabolome Using Novel Isotope-Coded Pyrylium Salt Derivatization and LC-MS: Herbs and Cancer Tissues as Cases

The amine submetabolome, including amino acids (AAs) and biogenic amines (BAs), is a class of small molecular compounds exhibiting important physiological activities. Here, a new pyrylium salt named 6,7-dimethoxy-3-methyl isochromenylium tetrafluoroborate ([d₀]-DMMIC) with stable isotope-labeled reagents ([d₃]-/[d₆]-DMMIC) was designed and synthesized for amino compounds. [d₀]-/[d₃]-/[d₆]-DMMIC-derivatized had a charged tag and formed a set of molecular ions with an increase of 3.02 m/z and the characteristic fragment ions of m/z 204.1:207.1:210.1. When DMMIC coupled with liquid chromatography-mass spectrometry (LC-MS), a systematic methodology evaluation for quantitation proved to have good linearity (R² between 0.9904 and 0.9998), precision (interday: 2.2-21.9%; intraday: 1.0-19.7%), and accuracy (recovery: 71.8-108.8%) through the test AAs. Finally, the methods based on DMMIC and LC-MS demonstrated the advantaged application by the nontargeted screening of BAs in a common medicinal herb Senecio scandens and an analysis of metabolic differences among the amine submetabolomes between the carcinoma and paracarcinoma tissues of esophageal squamous cell carcinoma (ESCC). A total of 20 BA candidates were discovered in S. scandens as well as the finding of 13 amine metabolites might be the highest-potential differential metabolites in ESCC. The results showed the ability of DMMIC coupled with LC-MS to analyze the amine submetabolome in herbs and clinical tissues.

Uptake and Metabolization of Serotonin by Granulosa Cells Form a Functional Barrier in the Mouse Ovary

Serotonin (5-HT) plays an essential role in regulating female reproductive function in many animals. 5-HT accumulates in the mammalian ovary with the involvement of membrane serotonin transporter SERT and is functionally active in the oocytes of growing follicles, but shows almost no activity in follicular cells. In this study, we clarified the interplay between 5-HT membrane transport and its degradation by monoamine oxidase (MAO) in the mammalian ovary. Using pharmacologic agents and immunohistochemical staining of the cryosections of ovaries after serotonin administration in vitro, we demonstrated the activity of transport and degradation systems in ovarian follicles. The MAO inhibitor pargyline increased serotonin accumulation in the granulosa cells of growing follicles, indicating the activity of both serotonin uptake and degradation by MAO in these cells. The activity of MAO and the specificity of the membrane transport of serotonin was confirmed in primary granulosa cell culture treated with pargyline and fluoxetine. Moreover, the accumulation of serotonin is more effective in the denuded oocytes and occurs at lower concentrations than in the oocytes within the follicles. This confirms that the activity of SERT and MAO in the granulosa cells surrounding the oocytes impedes the accumulation of serotonin in the oocytes and forms a functional barrier to serotonin.

Atlas of receptor genes expressed by the bovine morula and corresponding ligand-related genes expressed by uterine endometrium

Regulation of the mammalian embryo involves cell‐signaling molecules produced by the maternal oviduct and endometrium. Here, datasets on the transcriptome of the gestational Days 5 and 6 bovine morula and Day 5 maternal endometrium were examined to identify receptor genes expressed by the morula and expression of the corresponding ligand‐related genes in the endometrium. A total of 175 receptor genes were identified in the morula, including 48 encoding for growth factors or WNT signaling molecules, 25 for cytokines and chemokines, 35 involved in juxtacrine and matricellular signaling and 25 encoding for receptors for small molecules. Some of the highly‐expressed pairs of endometrial ligand and embryo receptor genes included MDK and its receptors ITGB1, SDC4 and LRP2, WNT5A (RYK), VEGFA (ITGB1), GPI (AMFR), and the hedgehog proteins IHH and DHH (HHIP). The most highly expressed receptors for small molecules were GPRC5C (retinoic acid receptor), PGRMC1 (progesterone), and CHRNB2 (acetylcholine). There were also 84 genes encoding for cell signaling ligands expressed by the morula, with the most highly expressed being GPI, AIMP1, TIMP1, IK, and CCN2. The atlas of receptor and ligand genes should prove useful for understanding details of the communication between the embryo and mother that underlies optimal embryonic development.

Profiling and integrated analysis of whole-transcriptome changes in uterine caruncles of pregnant and non-pregnant buffaloes

Improved reproductive performance in buffaloes can be achieved by understanding the basic mechanism governing the embryonic attachment and feto-maternal communication. Considering this, trascriptomic profiling and integrative analysis of long intergenic non-coding RNAs were carried out in the uterine caruncles of pregnant and non-pregnant buffaloes. Transcriptome data of pregnant and non-pregnant uterine caruncles after quality control was used to perform the analysis. Total of 86 novel lincRNAs expressed in uterine caruncular tissues were identified and characterized. Differential expression analysis revealed that 447 mRNAs and 185 mRNAs were up- and down- regulated, respectively. The number of up- and down- regulated lincRNAs were 114 and 13, respectively. Of the identified 86 novel lincRNAs, six novel lincRNAs were up-regulated in the pregnant uterine caruncles. GO terms (biological process) and PANTHER pathways associated with reproduction and embryogenesis were over-represented in differentially expressed genes. Through miRNA interaction analysis, interactions of 16 differentially expressed lincRNAs with mi-RNAs involved in reproduction were identified. This study has provided a catalogue of differentially expressed genes and novel regions previously unknown to play a significant role in buffalo reproduction. The results from the current study extends the buffalo uterine lncRNAs database and provides candidate regulators for future molecular genetic studies on buffalo uterine physiology to improve the embryo implantation and successful completion of pregnancy.

The effect of antenatal depression and antidepressant treatment on placental tissue: a protein-validated gene expression study

Background

Antenatal depression affects 10–20% of pregnant women. Around 2–4% of European pregnant women use antidepressant treatment, most commonly selective serotonin reuptake inhibitors (SSRIs). Poor pregnancy outcomes, such as preterm birth and low birth weight, have been described in women with antenatal depression and in pregnant women on SSRI treatment. However, the effects of antenatal depression and antidepressant treatment on the placenta are largely unknown. The aim of this work was to compare placental gene and protein expression in healthy women, women with untreated antenatal depression and women on antidepressant treatment during pregnancy.

Methods

Placental samples from 47 controls, 25 depressed and 45 SSRI-treated women were analysed by means of qPCR using custom-designed TaqMan low-density arrays (TLDAs) for 44 genes previously known to be involved in the pathophysiology of depression, and expressed in the placenta. Moreover, placental protein expression was determined by means of immunohistochemistry in 37 healthy controls, 13 women with untreated depression and 21 women on antidepressant treatment. Statistical comparisons between groups were performed by one-way ANOVA or the Kruskal–Wallis test.

Results

Nominally significant findings were noted for HTR1A and NPY2R, where women with untreated depression displayed higher gene expression than healthy controls (p < 0.05), whereas women on antidepressant treatment had similar expression as healthy controls. The protein expression analyses revealed higher expression of HTR1A in placentas from women on antidepressant treatment, than in placentas from healthy controls (p < 0.05).

Conclusion

The differentially expressed HTR1A, both at the gene and the protein level that was revealed in this study, suggests the involvement of HTR1A in the effect of antenatal depression on biological mechanisms in the placenta. More research is needed to elucidate the role of depression and antidepressant treatment on the placenta, and, further, the effect on the fetus.

5-Hydroxytryptophan (5-HTP)-induced intracellular syndrome in mouse non-neural embryonic cells is associated with inhibited proliferation and cell death

Biogenic monoamines are involved in the regulation of various processes in both neural and non-neural cells during development. The present study aimed to identify the regulatory effects of serotonin (5-HT) and its precursors (l-tryptophan and 5-hydroxytryptophan, 5-HTP) on proliferation and cell death in mouse embryonic stem cells (ESCs) and embryonic fibroblasts (MEFs and 3T3 cells). The concentration-dependent cell growth and viability of the ESCs, MEFs and 3T3 cells were analyzed after treatment with l-tryptophan, 5-HTP and 5-HT in the concentration range 10^-6 - 10^-2 M. Treating the cells with 5-HTP, but not l-tryptophan and 5-HT, induced reversible toxic effects. 5-HTP treatment (10^-3 - 10^-2 M) significantly inhibited cell proliferation through blocking of the S-phase of the cell cycle and increasing apoptotic and necrotic cell death. Moreover, 5-HTP treatment stimulated a reorganization of the actin and tubulin networks and upregulated the gene expression of enzymes involved in 5-HT synthesis and metabolism: aromatic amino acid decarboxylase (Aadc/Ddc), monoamine oxidase A (Maoa), and transglutaminase 2 (Tgm2). HPLC analysis found no changes in the intracellular and extracellular levels of 5-HT after 5-HTP treatment, but a significant increase of intracellular 5-HTP levels. However, inhibition of AADC with NSD-1015 or transglutaminase with cystamine prevented 5-HTP-induced cell growth impairment and attenuated the toxic effects of 5-HTP treatment. Our results suggest that 5-HTP can induce toxic effects through cell cycle arrest and cell death in embryonic stem and somatic cells by enhancing the levels of 5-HT-mediated protein modifications. This article is part of the special issue entitled 'Serotonin Research: Crossing Scales and Boundaries'.

Fipronil causes toxicity in mouse preimplantation embryos

In this study the possible toxicity of phenylpyrazole fipronil, the related commercial product FIPRON spot-on as well as FIPRON spot-on secondary ingredients on the developmental capacities and quality of mouse preimplantation embryos was evaluated. During in vitro tests, isolated two-cell stage embryos were cultured in media with addition of the listed chemicals until blastocyst formation. Stereomicroscopic evaluation of in vitro produced embryos showed that fipronil at 1 μM and higher concentration negatively affected embryonic development. Fluorescence staining revealed that the obtained blastocysts displayed lower numbers of blastomeres at 10 μM concentrations and elevated incidence of cell death from 1 μM concentration. The presence of FIPRON spot-on at a concentration equivalent to 10 μM of fipronil caused massive degeneration of all embryos. Secondary ingredients (butylhydroxyanisolum, butylhydroxytoluenum) at corresponding concentrations negatively impacted the development and quality of preimplantation embryos as well. During in vivo tests (daily oral administration of fipronil during the preimplantation period) in embryos collected from treated mouse females, significantly elevated incidence of cell death was observed even at the acute reference dose. Fipronil impaired the development and quality of mouse preimplantation embryos in both in vitro and in vivo tests. Embryotoxicity of the commercial product FIPRON spot-on was potentiated by the presence of secondary ingredients.

Effects of selective serotonin-reuptake inhibitors (SSRIs) on human villous trophoblasts syncytialization

Selective serotonin-reuptake inhibitors (SSRIs) are the most commonly prescribed antidepressants during pregnancy. The human placenta is a highly specialized organ supporting normal growth and development of the fetus. Therefore, this study aims to analyze the effects of SSRIs on villous cytotrophoblasts cells, using BeWo cells and human placental trophoblast cells in primary culture. The SSRIs fluoxetine and its metabolite norfluoxetine, sertraline and venlafaxine did not affect BeWo cell proliferation and viability, nor the percentage of M30-positive (apoptotic) primary trophoblast cells. None of the SSRIs affected basal or forskolin-stimulated BeWo cell fusion, whereas sertraline and venlafaxine increased the fusion of primary villous trophoblasts. Sertraline and venlafaxine also modified human chorionic gonadotropin beta (β-hCG) secretion by BeWo cells, whereas none of the SSRIs affected β-hCG secretion in primary trophoblasts. Norfluoxetine increased CGB (chorionic gonadotropin beta) and GJA1 (gap junction protein alpha 1) levels of gene expression (biomarkers of syncytialization) in BeWo cells, whereas in primary trophoblasts none of the SSRIs tested affected the expression of these genes. This study shows that SSRIs affect villous trophoblast syncytialization in a structure- and concentration-dependent manner and suggests that certain SSRIs may compromise placental health. In addition, it highlights the importance of using primary trophoblast cells instead of "trophoblast -like" cell lines to assess the effects of medications on human villous trophoblast function.

Exposure to neonicotinoid insecticides induces embryotoxicity in mice and rabbits

The potential toxicity of neonicotinoids (thiacloprid, acetamiprid, thiamethoxam and clothianidin) as well as related commercial products Calypso 480SC (thiacloprid mixture), Mospilan 20SP (acetamiprid mixture) and Agita 10WG (thiamethoxam mixture) on developmental capacities and quality of preimplantation embryos was evaluated. During in vitro tests, isolated 2-cell stage mice embryos were cultured in media with various concentrations of active compounds or commercial products until blastocyst formation. As found using stereomicroscopic examination, all neonicotinoids at highest (100μM) concentration negatively affected embryonic development (P<0.001). Fluorescence staining revealed that the blastocysts obtained displayed lower numbers of blastomeres and elevated incidence of cell death. Thiacloprid and acetamiprid decreased quality of blastocysts also at 10μM concentration. From the tested products only Calypso 480SC containing 10μM of thiacloprid showed harmful impact on embryo quality. In an experiment using rabbit embryos, similar negative effect of thiacloprid in vitro was recorded. In vivo testing confirmed that blastocysts collected from thiacloprid-treated mice displayed lower total cell counts than blastocysts from controls. The sensitivity of embryonic cells to neonicotinoids is in the order of thiacloprid>acetamiprid, thiomethoxam>clothianidin. Thiacloprid impairs development and quality of both mouse and rabbit preimplantation embryos, and shows embryotoxicity even at acute reference dose.

Autocrine embryotropins revisited: how do embryos communicate with each other in vitro when cultured in groups?

In the absence of the maternal genital tract, preimplantation embryos can develop in vitro in culture medium where all communication with the oviduct or uterus is absent. In several mammalian species, it has been observed that embryos cultured in groups thrive better than those cultured singly. Here we argue that group-cultured embryos are able to promote their own development in vitro by the production of autocrine embryotropins that putatively serve as a communication tool. The concept of effective communication implies an origin, a signalling agent, and finally a recipient that is able to decode the message. We illustrate this concept by demonstrating that preimplantation embryos are able to secrete autocrine factors in several ways, including active secretion, passive outflow, or as messengers bound to a molecular vehicle or transported within extracellular vesicles. Likewise, we broaden the traditional view that inter-embryo communication is dictated mainly by growth factors, by discussing a wide range of other biochemical messengers including proteins, lipids, neurotransmitters, saccharides, and microRNAs, all of which can be exchanged among embryos cultured in a group. Finally, we describe how different classes of messenger molecules are decoded by the embryo and influence embryo development by triggering different pathways. When autocrine embryotropins such as insulin-like growth factor-I (IGF-I) or platelet activating factor (PAF) bind to their appropriate receptor, the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) pathway will be activated which is important for embryo survival. On the other hand, the mitogen-activated protein kinase (MAPK) pathway is activated when compounds such as hyaluronic acid and serotonin bind to their respective receptors, thereby acting as growth factors. By activating the peroxisome-proliferator-activated receptor family (PPAR) pathway, lipophilic autocrine factors such as prostaglandins or fatty acids have both survival and anti-apoptotic functions. In conclusion, considering different types of messenger molecules simultaneously will be crucial to understanding more comprehensively how embryos communicate with each other in group-culture systems. This approach will assist in the development of novel media for single-embryo culture.

Adrenergic DNA damage of embryonic pluripotent cells via β2 receptor signalling

Embryonic pluripotent cells are sensitive to genotoxicity though they need more stringent genome integrity to avoid compromising multiple cell lineages and subsequent generations. However it remains unknown whether the cells are susceptible to adrenergic stress which can induce somatic cell genome lesion. We have revealed that adrenergic stress mediators cause DNA damage of the cells through the β2 adrenergic receptor/adenylate cyclase/cAMP/PKA signalling pathway involving an induction of intracellular reactive oxygen species (ROS) accumulation. The adrenergic stress agonists adrenaline, noradrenaline, and isoprenaline caused DNA damage and apoptosis of embryonic stem (ES) cells and embryonal carcinoma stem cells. The effects were mimicked by β2 receptor-coupled signalling molecules and abrogated by selective blockade of β2 receptors and inhibition of the receptor signalling pathway. RNA interference targeting β2 receptors of ES cells conferred the cells the ability to resist the DNA damage and apoptosis. In addition, adrenergic stimulation caused a consistent accumulation of ROS in the cells and the effect was abrogated by β2 receptor blockade; quenching of ROS reversed the induced DNA damage. This finding will improve the understanding of the stem cell regulatory physiology/pathophysiology in an adrenergic receptor subtype signalling mechanism.

β2-Adrenoreceptor-Mediated Proliferation Inhibition of Embryonic Pluripotent Stem Cells

Adrenoreceptors (ARs) are widely expressed and play essential roles throughout the body. Different subtype adrenoceptors elicit distinct effects on cell proliferation, but knowledge remains scarce about the subtype-specific effects of β2-ARs on the proliferation of embryonic pluripotent stem (PS) cells that represent different characteristics of proliferation and cell cycle regulation with the somatic cells. Herein, we identified a β2-AR/AC/cAMP/PKA signaling pathway in embryonic PS cells and found that the pathway stimulation inhibited proliferation and cell cycle progression involving modulating the stem cell growth and cycle regulatory machinery. Embryonic stem (ES) cells and embryonal carcinoma stem (ECS) cells expressed functional β-ARs coupled to AC/cAMP/PKA signaling. Agonistic activation of β-ARs led to embryonic PS cell cycle arrest and proliferation inhibition. Pharmacological and genetic analyzes using receptor subtype blocking and RNA interference approaches revealed that this effect selectively depended on β2-AR signaling involving the regulation of AKT, ERK, Rb, and Cyclin E molecules. Better understanding of the effects of β2-ARs on embryonic PS cell proliferation and cycle progression may provide new insights into stem cell biology and afford the opportunity for exploiting more selective ligands targeting the receptor subtype for the modulation of stem cells.

Soluble ligands and their receptors in human embryo development and implantation

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

The effect of antenatal depression and selective serotonin reuptake inhibitor treatment on nerve growth factor signaling in human placenta

Depressive symptoms during pregnancy are common and may have impact on the developing child. Selective serotonin reuptake inhibitors (SSRIs) are the most prescribed antidepressant treatment, but unfortunately, these treatments can also negatively affect the behavioral development and health of a child during pregnancy. In addition, serotonin (5-HT) exerts neurotrophic actions with thus far not fully known effects in the offspring. The neurotrophic growth factor (NGF) is involved in neuronal cell survival and differentiation, and altered placenta levels have been found to increase the risk for pregnancy complications, similar to those found in women treated with SSRIs. We therefore investigated whether the NGF signaling pathway was altered in the placenta from women treated with SSRIs (n = 12) and compared them with placenta from depressed (n = 12) and healthy mothers (n = 12). Results from immunohistochemical stainings revealed that placental NGF protein levels of SSRI-treated women were increased in both trophoblasts and endothelial cells compared with depressed and control women. In addition, downstream of the NGF receptor TrkA, increased levels of the signaling proteins ROCK2 and phosphorylated Raf-1 were found in stromal cells and a tendency towards increased levels of ROCK2 in trophoblasts and endothelial cells in SSRI-treated women when compared to healthy controls. SSRI-treated women also displayed increased levels of phosphorylated ROCK2 in all placental cell types studied in comparison with depressed and control women. Interestingly, in placental endothelial cells from depressed women, NGF levels were significantly lower compared to control women, but ROCK2 levels were increased compared with control and SSRI-treated women. Taken together, these results show that the NGF signaling and downstream pathways in the placenta are affected by SSRI treatment and/or antenatal depression. This might lead to an altered placental function, although the clinical relevance of our findings still needs to be investigated.

Monoamine oxidases in development

Monoamine oxidases (MAOs) are flavoproteins of the outer mitochondrial membrane that catalyze the oxidative deamination of biogenic and xenobiotic amines. In mammals there are two isoforms (MAO-A and MAO-B) that can be distinguished on the basis of their substrate specificity and their sensitivity towards specific inhibitors. Both isoforms are expressed in most tissues, but their expression in the central nervous system and their ability to metabolize monoaminergic neurotransmitters have focused MAO research on the functionality of the mature brain. MAO activities have been related to neurodegenerative diseases as well as to neurological and psychiatric disorders. More recently evidence has been accumulating indicating that MAO isoforms are expressed not only in adult mammals, but also before birth, and that defective MAO expression induces developmental abnormalities in particular of the brain. This review is aimed at summarizing and critically evaluating the new findings on the developmental functions of MAO isoforms during embryogenesis.

Ginsenoside rb1 modulates level of monoamine neurotransmitters in mice frontal cortex and cerebellum in response to immobilization stress

Cerebral monoamines play important roles as neurotransmitters that are associated with various stressful stimuli. Some components such as ginsenosides (triterpenoidal glycosides derived from the Ginseng Radix) may interact with monoamine systems. The aim of this study was to determine whether ginsenoside Rb1 can modulate levels of the monoamines such as dihydroxyphenylalanine (DOPA), dopamine (DA), norepinephrine (NE), epinephrine (EP), 3,4-dihydroxyphenylacetic acid (DOPAC), 5-hydorxytryptamine (5-HT), 5-hydroxindole-3-acetic acid (5-HIAA), and 5-hydroxytryptophan (5-HTP) in mice frontal cortex and cerebellum in response to immobilization stress. Mice were treated with ginsenoside Rb1 (10 mg/kg, oral) before a single 30 min immobilization stress. Acute immobilization stress resulted in elevation of monoamine levels in frontal cortex and cerebellum. Pretreatment with ginsenoside Rb1 attenuated the stress-induced changes in the levels of monoamines in each region. The present findings showed the anti-stress potential of ginsenoside Rb1 in relation to regulation effects on the cerebral monoaminergic systems. Therefore, the ginsenoside Rb1 may be a useful candidate for treating several brain symptoms related with stress.

Proteomic characterization of histotroph during the preimplantation phase of the estrous cycle in cattle

Uterine secretions, or histotroph, are a critical component for early embryo survival, functioning as the sole supply of vitamins, minerals, enzymes, and other myriad of nutrients required by the developing conceptus before implantation. Histotroph is therefore a promising source for biomarkers of uterine function and for enhancing our understanding of the environment supporting early embryo development and survival. Utilizing label-free liquid chromatography-tandem mass spectrometry (LC-MS/MS) shotgun proteomics, we characterized the uterine proteome at two key preimplantation stages of the estrous cycle in high fertility cattle. We identified 300 proteins on Day 7 and 510 proteins on Day 13 including 281 proteins shared between days. Five proteins were more abundant (P < 0.05) on Day 7 compared with Day 13 and included novel histotroph proteins cytokeratin 10 and stathmin. Twenty-nine proteins were more abundant (P < 0.05) including 13 unique on Day 13 compared with Day 7 and included previously identified legumain, metalloprotease inhibitor-2, and novel histotroph proteins chromogranin A and pyridoxal kinase. Functional analysis of the 34 differentially expressed proteins (including 14 novel to histotroph) revealed distinct biological roles putatively involved in early pregnancy, including remodelling of the uterine environment in preparation for implantation; nutrient metabolism; embryo growth, development and protection; maintenance of uterine health; and maternal immune modulation. This study is the first reported LC-MS/MS based global proteomic characterization of the uterine environment in any domesticated species before implantation and provides novel information on the temporal alterations in histotroph composition during critical stages for early embryo development and uterine function during the early establishment of pregnancy.