Arginine enhances embryo implantation in rats through PI3K/PKB/mTOR/NO signaling pathway during early pregnancy

Our previous study has demonstrated that dietary arginine supplementation during early pregnancy enhanced embryo implantation in rats. However, the mechanism was not clear. The objective of this study was to determine the mechanism that arginine enhanced embryo implantation during early pregnancy. Rats were fed the basal diets supplemented with 1.3% (wt:wt)l-arginine–HCl or 2.2% (wt:wt)l-alanine (isonitrogenous control) once pregnancy. On d4 of pregnancy, rats were given intrauterine injection ofl-NG-nitro arginine methyl ester (l-NAME, nitric oxide synthase inhibitor), α-difluoromethylornithine (DFMO, polyamine synthesis inhibitor), wortmannin (PI3K inhibitor), or rapamycin (mTOR inhibitor). On d7 of pregnancy, rats were killed. Intrauterine injection ofl-NAME decreased the implantation sites, while dietary arginine supplementation increased the implantation sites. Intrauterine injection of DFMO decreased the pregnancy rate, which was reversed by dietary arginine supplementation. Intrauterine injection of rapamycin or wortmannin inhibited embryo implantation. However, dietary arginine supplementation did not reverse this inhibition. Western blot analysis revealed that the expression of uterine p-PKB and p-S6K1 was greater in rats fed the arginine-supplemented diet in the presence ofl-NAME treatment compared with rats fed the control diet. In the presence of DFMO treatment, the expression of uterine iNOS and eNOS was significantly enhanced in the arginine group compared with the control group. Similarly, intrauterine injection of wortmannin or rapamycin decreased the expression of uterine iNOS and eNOS, which was enhanced by dietary arginine supplementation. These data indicated that dietary arginine supplementation during early pregnancy could enhance embryo implantation through stimulation of PI3K/PKB/mTOR/NO signaling pathway.

Download Full-text

Platelet-activating factor-antagonists reduce implantation in mice at low doses only

Reproduction Fertility and Development ◽

10.1071/rd9950051 ◽

1995 ◽

Vol 7 (1) ◽

pp. 51 ◽

Cited By ~ 10

Author(s):

C O'Neill

Keyword(s):

Early Pregnancy ◽

Embryo Implantation ◽

Platelet Activating Factor ◽

Implantation Rate ◽

Corpora Lutea ◽

Detailed Knowledge ◽

Low Doses ◽

Paf Antagonists ◽

Implantation Sites ◽

Web 2086

The effects of a number of platelet-activating factor (PAF)-antagonists on embryo implantation were investigated. Mice were treated from Day 1 to Day 4 of pregnancy with three defined PAF-antagonists: SRI 63 441, BN 52021, and WEB 2086. Necroscopies were performed on Day 8 and the number of implantation sites, the implantation rate (number of implanted embryos compared with the number of corpora lutea) and the proportion of animals pregnant were determined. Each agent caused a reduction in the number of implantation sites at relatively low doses. The dose that had a maximum contragestational effect was 40 micrograms, 10 micrograms and 10 micrograms (per 30 g bodyweight per day) for SRI 63 441, WEB 2086 and BN 52021 respectively. This contragestational effect was completely lost at twice (SRI 63 441), five times (WEB 2086) and ten times (BN 52021) the most effective dose. Treatment with WEB 2086 on the day of implantation (Day 4) by intraperitoneal injection or instillation into the uterus only did not significantly reduce the implantation rate and neither did treatment after implantation (Days 5-8). The results show that the pharmacology of PAF-antagonists in early pregnancy is not simple. An understanding of the actions of these agents in early pregnancy will require a detailed knowledge of their pharmacokinetics, pharmacodynamics and targets of action in early pregnancy.

Download Full-text

The Characterization of Ground Raspberry Seeds and the Physiological Response to Supplementation in Hypertensive and Normotensive Rats

Nutrients ◽

10.3390/nu12061630 ◽

2020 ◽

Vol 12 (6) ◽

pp. 1630

Author(s):

Michał Majewski ◽

Ewa Kucharczyk ◽

Roman Kaliszan ◽

Michał Markuszewski ◽

Bartosz Fotschki ◽

...

Keyword(s):

Essential Fatty Acids ◽

Control Diet ◽

Protective Role ◽

Atherogenic Index ◽

Control Group ◽

Synthesis Inhibitor ◽

Cox Inhibitor ◽

Cox 2 ◽

Wistar Kyoto ◽

Main Component

This study aimed to evaluate the protective role of ground raspberry seeds (RBS) as a source of polyphenols and essential fatty acids on blood plasma enzymatic antioxidant status, lipid profile, and endothelium-intact vasodilation during physiological and pathological conditions. Young normotensive Wistar–Kyoto rats (WKYs) and spontaneously hypertensive rats (SHRs) at ten weeks of age were fed with either a control diet or were supplemented with added 7% RBS for six weeks (n = 6). The main component of RBS was dietary fiber (64%) and the main polyphenols were ellagitannins (1.2%) and flavan-3-ols (0.45%). Irrespective of the rat model, ground RBS decreased liver enzyme aspartate aminotransferase (0.9-fold) and hydrogen peroxide scavenging capacity (Catalase, 0.9-fold). In supplemented SHRs, preincubation with inducible nitric oxide synthase (iNOS) inhibitor 1400W, nonselective cyclooxygenase (COX) inhibitor indomethacin, selective COX-2 inhibitor NS-398, prostacyclin (PGI2) synthesis inhibitor tranylcypromine (TCP), thromboxane receptor (TP) antagonist SQ-29548, thromboxane synthesis inhibitor furegrelate, and 20-HETE synthesis inhibitor HET0016 induced the same relaxant response to acetylcholine as in the nonsupplemented control group. In supplemented WKYs, atherogenic index was decreased (0.8-fold), while iNOS and COX-2-derived PGI2 increased acetylcholine-induced vasodilation. These effects of ground RBS may constitute a potential mechanism for preventing cardiovascular diseases.

Download Full-text

Endometrial pyruvate kinase M2 is essential for decidualization during early pregnancy

Journal of Endocrinology ◽

10.1530/joe-19-0553 ◽

2020 ◽

Vol 245 (3) ◽

pp. 357-368 ◽

Cited By ~ 2

Author(s):

Yan Su ◽

Sujuan Guo ◽

Chunyan Liu ◽

Na Li ◽

Shuang Zhang ◽

...

Keyword(s):

Cell Proliferation ◽

Pyruvate Kinase ◽

Early Pregnancy ◽

Stromal Cells ◽

Embryo Implantation ◽

Pyruvate Kinase M2 ◽

Ishikawa Cells ◽

Implantation Sites

Embryo implantation is essential for normal pregnancy. Decidualization is known to facilitate embryo implantation and maintain pregnancy. Uterine stromal cells undergo transformation into decidual cells after embryo attachment to the endometrium. Pyruvate kinase M2 (PKM2) is a rate limiting enzyme in the glycolysis process which catalyzes phosphoenolpyruvic acid into pyruvate. However, little is known regarding the role of PKM2 during endometrial decidualization. In this study, PKM2 was found to be mainly located in the uterine glandular epithelium and luminal epithelium on day 1 and day 4 of pregnancy and strongly expressed in the decidual zone after embryo implantation. PKM2 was dramatically increased with the onset of decidualization. Upon further exploration, PKM2 was found to be more highly expressed at the implantation sites than at the inter-implantation sites on days 5 to 7 of pregnancy. PKM2 expression was also significantly increased after artificial decidualization both in vivo and in vitro. After PKM2 expression was knocked down by siRNA, the number of embryo implantation sites in mice on day 7 of pregnancy was significantly reduced, and the decidualization markers BMP2 and Hoxa10 were also obviously downregulated in vivo and in vitro. Downregulated PKM2 could also compromise cell proliferation in primary endometrial stromal cells and in Ishikawa cells. The migration rate of Ishikawa cells was also obviously suppressed by si-PKM2 according to the wound healing assay. In conclusion, PKM2 might play an important role in decidualization during early pregnancy, and cell proliferation might be one pathway for PKM2 regulated decidualization.

Download Full-text

The economic viability of L-arginine supplementation in diets for sows in the lactation phase

Revista Brasileira de Saúde e Produção Animal ◽

10.1590/s1519-9940210412020 ◽

2020 ◽

Vol 21 ◽

Author(s):

Débora Virginia RIBEIRO ◽

Leonardo da Silva FONSECA ◽

Rennan Herculano Rufino MOREIRA ◽

Caio Peixoto CHAIN ◽

Márvio Lobão Teixeira ABREU ◽

...

Keyword(s):

Economic Efficiency ◽

Control Diet ◽

Economic Viability ◽

Control Group ◽

Gross Margin ◽

Descriptive Case Study ◽

Lactation Phase ◽

The Cost ◽

Arginine Supplementation

ABSTRACT The objective of this study was to evaluate the economic viability of L-arginine supplementation in diets for sows during the lactation phase. A descriptive case study was carried out to identify the economic viability of the supplementation of L-arginine in the lactation ration, in relation to the control diet, on the productive performance of hyper prolific sows and their litters. The study was carried out on a commercial farm located in the state of Minas Gerais. It analyzed feasibility criteria such as the marginal physical product (MPPg) and gross margin (GM) in the scenario of technical and economic efficiency, which were compared to the GM in the control group. Technical efficiency was established at 0.71% of L-arginine in daily feed intake according to previous fieldwork by the authors, while economic efficiency obtained in this study was 0.43% supplementation. The relationship between the L-arginine price and the sale price of the piglets directly determined the economic viability, compared to the control group. Thus, initially considering the price of a piglet as R$ 9.76/kg, the cost of L-arginine should not exceed 6.61 times this value; that is, it is estimated at up to R$ 64.50. Therefore, at the final price of L-arginine of R$ 54.88, a piglet should be sold at a price of R$ 8.30/kg to make the supplementation of L-arginine in the diet of lactation-phase swine economically possible.

Download Full-text

Glycinin-induced porcine IPEC-J2 cells damage via the NF-κB/MAPK signaling pathway

10.21203/rs.3.rs-16881/v2 ◽

2020 ◽

Author(s):

Chenglu Peng ◽

Zhifeng Sun ◽

Lei Wang ◽

Yingshuang Shu ◽

Mengchu He ◽

...

Keyword(s):

Signaling Pathway ◽

Intestinal Barrier ◽

Mapk Signaling ◽

Mapk Signaling Pathway ◽

Control Group ◽

Epithelial Cell Line ◽

Pyrrolidine Dithiocarbamate ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

Nitric Oxide Synthase Inhibitor

Abstract Background: Glycinin, a protein found in soybean, is a human and animal allergen that causes damage to the intestinal barrier. However, its mechanisms of action remain unclear. Therefore, in this study, the intestinal porcine epithelial cell line IPEC-J2 was used to evaluate the effect of glycinin concentration on the intestinal epithelium and identify the related signaling pathways. Results: IPEC-J2 cells were divided into seven treatment groups and a control group; the cells were treated for 24 h with 1, 5, or 10 mg/mL glycinin or with 5 mg/mL glycinin after 30 min of pre-treatment with 1 μmol/L nuclear factor-kappa B (NF-κB) inhibitor (pyrrolidine dithiocarbamate), inducible nitric oxide synthase inhibitor ( N -ω-nitro-l-arginine methyl ester), Jun N-terminal kinase (JNK) inhibitor (SP600125), or p38 inhibitor (SB202190). A series of molecular and biochemical experiments revealed that the levels of NF-κB, p38, and JNK, as well as their downstream proteins, were increased after treatment compared to those in the control group. Conclusion: Glycinin damaged IPEC-J2 cells in a concentration-dependent manner via the NF-κB/MAPK signaling pathway.

Download Full-text

227.An inhibitor of leukemia inhibitory factor signalling blocks embryo implantation in the mouse

Reproduction Fertility and Development ◽

10.1071/srb04abs227 ◽

2004 ◽

Vol 16 (9) ◽

pp. 227

Author(s):

E. Dimitriadis ◽

C. Stoikos ◽

M. Baca ◽

W. Fairlie ◽

A. D. Uboldi ◽

...

Keyword(s):

Early Pregnancy ◽

Leukemia Inhibitory Factor ◽

Embryo Implantation ◽

Uterine Horn ◽

Inhibitory Factor ◽

Luminal Epithelium ◽

Pregnant Uterus ◽

Implantation Sites ◽

Post Implantation

Embryo implantation is a critical step in the establishment of pregnancy. Endometrial leukemia inhibitory factor (LIF) is essential for embryo implantation in the mouse (1). Uterine LIF is expressed in the luminal epithelium on Day 3 of pregnancy (D3) (D0�=�day of plug detection) and signals via activation of signal transducer and activator of transcription (Stat) 3 (2). We examined the effect of a novel LIF signalling inhibitor on the phosphorylation (p) of Stat3 during early pregnancy and on embryo implantation in the mouse. We injected LIF inhibitor into one uterine horn and PBS into the other uterine horn of the mouse at D3 and examined the effect on pStat3 immunostaining in the luminal epithelium between 30 and 360�min later. We found no immunoreactive pStat3 in luminal epithelium following treatment with LIF inhibitor at 60 and 90�min but variable staining at other time points. The PBS-treated uterine horn showed intense immunostaining at all times. LIF inhibitor (1mg/kg body weight per day) or PBS was administered to mice (a) subcutaneously, (b) intraperitoneally, at 8-hourly intervals for 3�days from D2, or (c) continuously into the peritoneal cavity via Alzet pumps from D2. No effect was seen on implantation at D6. When LIF antagonist (3.5mg/kg/day) or PBS were administered by Alzet pumps from D2 together with ip injections, 4-hourly from D3 for 36�h, there were no implantation sites in the uteri of treated mice (n�=�5) while the control mice (n�=�4) had 3.6��0.5�sites (P�<�0.001). Histologically, the uteri of the treated mice resembled non-pregnant uterus, while the control uterus resembled post-implantation uterus. The results demonstrate that treatment of mice during early pregnancy with a novel LIF inhibitor blocks LIF action in vivo and embryo implantation. This knowledge is important for development of novel contraceptives. (1) Stewart, C. L., Kaspar, P., Brunet, L. J., Bhatt, H., Gadi, I., Kontgen, F., Abbondanzo, S. J. (1992) Nature 359, 76–79. (2) Cheng, J. G., Chen, J. R., Hernandez, L., Alvord, W. G., Stewart, C. L. (2001) Proc. Natl Acad. Sci. USA 98, 8680–8685.

Download Full-text

Expression of DNA methyltransferases in the mouse uterus during early pregnancy and susceptibility to dietary folate deficiency

Reproduction ◽

10.1530/rep-12-0006 ◽

2012 ◽

Vol 144 (1) ◽

pp. 91-100 ◽

Cited By ~ 17

Author(s):

Y B Ding ◽

J L He ◽

X Q Liu ◽

X M Chen ◽

C L Long ◽

...

Keyword(s):

Early Pregnancy ◽

Embryo Implantation ◽

Dna Methyltransferases ◽

Deficient Diet ◽

Mouse Uterus ◽

Dietary Folate ◽

Endometrial Cells ◽

Pregnant Mice ◽

Implantation Sites ◽

Significant Expression

We have characterized the uterine expression of DNA methyltransferases (DNMTs) during early pregnancy in mice and determined whether a folate-deficient diet (FDD) can affect DNMTs in this context. Within endometrial cells, expressions of DNMT (cytosine-5) 1 (Dnmt1),Dnmt3a, andDnmt3bwere significantly elevated during the prereceptive phase of pregnancy but generally returned to baseline levels during receptive and postimplantation periods. As such, the transcription of DNMT genes is temporally regulated during early pregnancy. When comparisons were made between implantation sites (IS) and inter-IS on day 5 of pregnancy, lower levels ofDnmt3awere detected at IS. Comparisons between IS and inter-IS did not reveal significant expression differences for other DNMT genes. When tissue sections were examined, DNMT3A was specifically lower in the stroma of IS. Reduced DNMT1 and DNMT3B levels were also observed in the luminal and glandular epithelia of IS, whereas no obvious differences in the stroma were detected. In pseudo-pregnant mice subjected to a FDD, levels ofDnmt1andDnmt3a(but notDnmt3b) were significantly upregulated in endometrial tissues, as compared with controls. When tissues from these folate-deficient mice were examined, DNMT1 levels were elevated in both the luminal and glandular epithelia, whereas DNMT3A was upregulated in the luminal epithelium and the stroma. A slight increase in DNMT3B levels was detected in the glandular epithelium. These results indicate that DNMTs may regulate the transcription of endometrial genes associated with embryo implantation and that levels of DNMTs are affected by dietary folate in mice.

Download Full-text

Expression and function of Pdcd4 in mouse endometrium during early pregnancy

Reproduction ◽

10.1530/rep-17-0787 ◽

2018 ◽

Vol 155 (4) ◽

pp. 393-402 ◽

Cited By ~ 5

Author(s):

Yue Zhang ◽

Mingyun Ni ◽

Na Liu ◽

Yongjiang Zhou ◽

Xuemei Chen ◽

...

Keyword(s):

Early Pregnancy ◽

Quantitative Polymerase Chain Reaction ◽

Embryo Implantation ◽

Complex Process ◽

Programmed Cell Death 4 ◽

Implantation Sites ◽

And Function

Embryo implantation is a complex process involving synchronised crosstalk between a receptive endometrium and functional blastocysts. Apoptosis plays an important role in this process as well as in the maintenance of pregnancy. In this study, we analysed the expression pattern of programmed cell death 4 (Pdcd4), a gene associated with apoptosis in the mouse endometrium, during early pregnancy and pseudopregnancy by real-time quantitative polymerase chain reaction, in situ hybridisation, Western blotting and immunohistochemistry. The results showed that Pdcd4 was increased along with days of pregnancy and significantly reduced at implantation sites (IS) from day 5 of pregnancy (D5). The level of Pdcd4 at IS was substantially lower than that at interimplantation sites (IIS) on D6 and D7. In addition, Pdcd4 expression in the endometrium was reduced in response to artificially induced decidualisation in vivo and in vitro. Downregulation of Pdcd4 gene expression in cultured primary stromal cells promoted decidualisation, while upregulation inhibited the decidualisation process by increasing apoptosis. These results demonstrate that Pdcd4 is involved in stromal cell decidualisation by mediating apoptosis and therefore plays a role in embryo implantation in mice.

Download Full-text

Testosterone Decreases the Number of Implanting Embryos, Expression of Pinopode and L-selectin Ligand (MECA-79) in the Endometrium of Early Pregnant Rats

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17072293 ◽

2020 ◽

Vol 17 (7) ◽

pp. 2293

Author(s):

Mohd Helmy Mokhtar ◽

Nelli Giribabu ◽

Naguib Salleh

Keyword(s):

Adverse Effect ◽

Early Pregnancy ◽

Structural Changes ◽

Embryo Implantation ◽

Normal Endometrium ◽

Pregnant Rats ◽

Selectin Ligand ◽

Implantation Sites

Testosterone could have adverse effect on fertility. In this study, we hypothesized that this hormone could reduce the number of embryo implantations via affecting the normal endometrium ultrastructure and expression of endometrial proteins involved in implantation. Therefore, the aims were to identify these adverse testosterone effects. Methods: Intact pregnant rats were given 250 or 500 µg/kg/day testosterone for three days, beginning from day 1 of pregnancy. Rats were euthanized either at day 4 to analyze the ultra-structural changes in the endometrium and expression and distribution of MECA-79 protein, or at day 6 to determine the number of implantation sites. Results: Administration of 500 µg/kg/day testosterone suppresses endometrial pinopodes development and down-regulates expression and distribution of MECA-79 protein in the uterus. In addition, the number of implantation sites were markedly decreased. Conclusions: Changes in endometrial ultrastructure and expression of implantation protein in the endometrium in early pregnancy period could be the reason for failure of embryo implantation under testosterone influence.

Download Full-text

Optimal levels of nitric oxide are crucial for implantation in mice

Reproduction Fertility and Development ◽

10.1071/rd99044 ◽

1999 ◽

Vol 11 (3) ◽

pp. 183 ◽

Cited By ~ 16

Author(s):

H. Ota ◽

S. Igarashi ◽

N. Oyama ◽

T. Tanaka ◽

Y. Suzuki

Keyword(s):

Nitric Oxide ◽

Embryo Implantation ◽

Critical Role ◽

Mature Female ◽

Pregnancy Rates ◽

Nitric Oxide Donor ◽

Control Group ◽

Dependent Manner ◽

Nitric Oxide Synthase Inhibitor ◽

Synthase Inhibitor

This study was performed to clarify the critical role of optimal levels of nitric oxide on fecun-dity in mice during the implantation period. Mature female pregnant mice were treated with either nitric oxide donor molsidomine (3, 15, 60 mg kg-1) or nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (L-name; 0.3, 1.5, 6 mg kg-1) every 12 h, seven times from the night of Day 2 to Day 5 of gestation. They were killed on Day 14 of gestation. Pregnancy rates in each group (n = 22) and the number of live or absorbed fetuses in each mouse was calculated. The pregnancy rates in the experimental group were reduced in a dose-dependent manner. The rate in the control group was 100%, whereas those in the 60-mg mol-sidomine and 6-mg L-name groups were 40.9 and 31.8%, respectively. Histological analysis of uteri on Day 5 of gestation after treatment with 60 mg molsidomine or 6 mg L-name suggested retarded decidualization of stromal cells or defective function of predecidualized cells. In conclusion, optimal levels of nitric oxide are crucial for endometrial function and embryo implantation.

Download Full-text