2014 Fiscal Year Research-status Report
Clarification of mechanisms regulating early embryo-uterine interactions in cattle
| Project/Area Number |
26450379
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| Research Institution | Obihiro University of Agriculture and Veterinary Medicine |
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Principal Investigator |
アコスタ トマス 帯広畜産大学, 畜産学部, 准教授 (80379718)
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| Project Period (FY) |
2014-04-01 – 2017-03-31
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| Keywords | Bovine / Embryo / Uterus / Early pregnancy / Embryonic loss / Uterine environment / Endometritis / Conceptus elongation |
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| Outline of Annual Research Achievements |
The understanding of the interaction between the conceptus and uterine environment is essential to ameliorate the embryonic loss in domestic animals. The present research aimed to reveal the local mechanisms of action of embryonic product (interferon tau; IFN and epidermal growth factor; EGF) on bovine uterus during the implantation and their interactions.
1) We found that EGF protein in endometrial tissues was higher around the time of implantation Days 8-12 post-ovulation than in the other luteal stages. EGFR mRNA expression was higher between Days 12-17 than in the other luteal stages.
2) In cultured bovine endometrial cells, both EGF protein concentration and EGFR mRNA expression were higher in epithelial cells than in stromal cells.
3) EGF regulates prostaglandin F2α (PGF2α) and prostaglandin E2 (PGE2) synthesis in cultured endometrial epithelial and stromal cells. In epithelial cells, EGF (10 and/or 100 nM) increased PGF2α and PGE2 secretion, but in stromal cells EGF (100 nM) increased PGF2α, but not PGE2 secretion.
These results indicate that 1) the highest amount of EGF is produced by bovine endometrium at the mid-luteal stage, 2) endometrial EGFR mRNA expressions are higher at mid and late-luteal stages than other stages, 3) EGF is expressed mainly by uterine epithelial cells and 4) EGF has the ability to increase PGE2 and PGF2α production in both epithelial and stromal cells and therefore may play a role in local regulation of uterine function.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
1) The methodology and experimental protocol for the first part of the experiments (collection of endometrial tissue), endometrial cell culture, mRNA and protein analysis were well established.
2) The results of the present research were presented in a local meeting (107th Annual Meeting of the Society for Reproduction and Development), two international meetings (9th International Ruminant Reproduction Symposium and 41st Annual Conference of the Embryo Transfer Society) and two scientific manuscript were published in international peer reviewed journals (Animal Reproduction and Reproduction in Domestic Animals).
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| Strategy for Future Research Activity |
研究実施計画
Validation of in vitro co-culture system to study embryo-uterine interactions and secretion of luteotropic and luteolytic factors.
Experiment1: In vivo produced embryos will be collected on Day 7 or on Day 13 at Field Center of Obihiro University Experimental Farm. In case that the number of embryos is not enough, embryos will be collected from private farms. In vitro produced embryos on Day8 post-fertilization will be cultured alone or on luminal epithelial and stromal cells after they reached confluence for additional 1-4 days. The capacity of embryos to produce interferon tau, epidermal growth factor and prostaglandins will be evaluated in the presence or absence of endometrial cells, cortisol and epidermal growth factor will be used as stimulants. Cultured cells will be used to determine the expressions of proteins involved in PGs biosynthesis.
a) To test how cortisol affects uterine PGF production in the presence of the conceptus or their secretory products (Interferon tau and EGF) according to the results of Experiment1, co-culture of endometrial cells and blastocyst will be used.
b) To clarify whether cortisone or cortisol is more important in controlling uterine function and embryo development, an inhibitor of 11beta-hydroxysteroid dehydrogenase will be used to determine individual effects of cortisone and cortisol on interferon tau and PGE production.
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| Causes of Carryover |
There was a decrease in the price of some reagents.
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| Expenditure Plan for Carryover Budget |
Will be used to cover a part of travel expenses to attend an International Conference.
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